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be very considerable-though to some extent dependent on the kind of iron used in the boiler as well as in the temperature-and often explosions thus ensue from the "breaking of the back" of the boiler. To keep the diameter of these boilers within bounds, the French have largely employed the compound form known as the Elephant boiler (Fig. 14). A boiler slightly differing from this in detail, but on the same principle, bears the name of the Retort boiler, Fig. 15. The next improvement aimed at economy, and gave us the Cornish boiler, Fig. 16. To obviate the weakness of the larger flued boilers of this class, Mr. Fairbairn introduced the Double-flued boiler, Fig. 17, about twenty-five years ago.

HIGH PRESSURE BOILERS.

These boilers are very safe, and in somewhat extensive use, though by no means to the extent they merit. Considerable numbers of Butterley boilers have been constructed (see Fig. 18), but although they are economical, they are very weak against pressure, and therefore proportionately dangerous. Many minor varieties of boilers might be mentioned. One class of boiler-from its dreadfully destructive nature-claims attention, namely the class used in ironworks. These boilers, surrounded by brickwork, and exposed to the fierce flames from the puddling furnaces, would be sufficiently destructive in any ordinary situation; but, placed as they are, in the very midst of a number of men, amongst whom, when

they explode, they scatter a death-dealing shower of bricks, iron, and water, with the frequent addition of some of the hot iron from the furnaces, the carnage produced is often frightful.

The Multi-flued boiler (see Figs. 19 and 20). demands but little notice, as it has not been found satisfactory in practice, since its economy in fuel is more than counterbalanced by its being troublesome to clean. The Multi-tubular boiler is still more economical in fuel, but also still more difficult of access for cleaning. It is also liable to leak at the bottom, and from those two causes is wanting in durability. It is particularly unsuited to foul feed-water. Amongst the improvements made in boilers of late years Adamson's

In

flanged joints in internal flues, and Galloway's conical tubes occupy most important places. The strength afforded by the flange joints is very great, and when the frequent collapse of long flues is taken into consideration, is very important. Galloway's tubes, Fig. 21, not only materially strengthen the flues, but they also add a most efficient heating surface, as the flame and gases strike almost at right angles to the metal, while the water rises at a slight angle from it, the best possible conditions for evaporation-and thus they are valuable economisers of fuel. They also cause a very brisk circulation, which further tends to economy, and to the preservation of the boiler by equalizing the temperature of the water throughout, and so preventing unequal strains. It is probable that if inner tubes were added, as shown in Fig. 22, that the efficiency would be still greater, as such inner tubes would separate the water into two currents, upwards and downwards. All the boilers we have hitherto noticed, differing as they do largely, inter se, have one peculiarity in common, namely, that they each contain a large volume of water and steam. case of an explosion there is, therefore, a correspondingly large supply of destructive material. Further, they are each to some extent deficient in economy of fuel, as they allow the heated gases to slide to too great an extent along their heating surfaces, not breaking up the current sufficiently; and they are also, as a rule, wanting in circulation. These last objections do not apply much to Galloway's boiler, the first does. Many attempts have been made to so construct boilers as to be free from these objections, and also to carry high pressures. An early labourer in this field was Dr. Ernst Alban, of Plau, who produced a very able and exhaustive treatise on boilers about a quarter of a century ago. He discusses pressures up to 1,000lb. per inch. He was the originator of some very ingenious water-tube boilers. As these boilers have, however, become obsolete, they hardly fall within the scope of the present article. James and others proposed tubular boilers, having an extra inner tube to promote circulation. These inner tubes by no means answered the purpose for which they were intended, as the upward and downward currents met each other at the tops of the two tubes-inner and outer-and the circulation was far from being satisfactory. Mr. Field combatted this difficulty by splaying the top of the inner tube, which thus become trumpetshaped. That the "Field" tube answered its purpose may be gathered from the favour it enjoys and the large number-upwards of 60,000-in use. It has been found extremely applicable to fire engines, as it is a very rapid generator, so much so, that steam of 100lb. per inch has been raised from water at about 45° Fahr. in 74 minutes, in a boiler fitted with these tubes. These boilers are extremely suitable where quickness, high pressure and economy of fuel are required; and where constant and competent supervision is given to the firing and "feeding." They are not likely, however, to be generally adopted for factory and other uses where more liability and neglect exists. We have now to notice a boiler which is, perhaps, in most respects the best yet introduced. The one we allude to is Howard's Safety Boiler. This boiler possesses the following requisites of a good steam generator :-It affords ample heating surface of the very best kind for efficiency, as the flames and currents of gas are thoroughly broken up by the alternations of the vertical tubes. It offers a maximum amount of safety at high pressures; in fact, it is doubtful whether more than one tube would go at a time, even if an explosion did occur, which is very unlikely, as the tubes being small are of enormous strength, and are further, by reason of their shape, subject to simple tensile strains only, and therefore no very extensive damage would be likely to accrue. It also acts as a very efficient superheater, thus giving the two great advantages of very high and perfectly dry steam. Inasmuch as corrosion and scaling are undoubtedly the two most serious evils which have at all times attended boilers, so must importance attach to the fact that in Howard's boiler so good a circulation is obtained as to do away with the accumulation of scale. A further great advantage lies in its non-liability to injurious strains, as its construction admits of its yielding in all directions to the expansion and contraction consequent on changes of temperature. This boiler is also remarkably easy to repair. The only drawback to it lies in the rapidity with which the water will rise or fall in it. This difficulty is nowadays met, to a great extent, by Giffard's injector; but it must be borne in mind that the very class of users most likely to neglect their

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Blankley's Compound Selenite Stage, giving 28 changes of tint and colour.
ACCESSORIES TO THE MICROSCOPE.

boilers are also least likely to adopt so beautiful
a contrivance as the injector. In fact, the writer
himself some little time back took out an old
feed pump and put an injector in its place, which
gave the utmost satisfaction. Some little time
after the boiler passed from under his control,
when the pump was reinstated, merely on the
plea that the injector was "too scientific."

As regards the future of steam boilers, we may
expect that high pressures will continue to be-
come more general as their economy is more
widely appreciated. At the same time, let us
hope that the increased dangers resulting may be
guarded against by an efficient system of inspec-
tion and improved workmanship and materials in
the boilers, with the more extended use of double
lock-up safety valves and alarums, fusible plugs,
and trustworthy water and steam gauges in du-
plicate. At the present time it is dreadful to
contemplate the numbers of boilers working
literally at random. The writer went a few days
back to a place where they had had an explosion
of a boiler, which, though fortunately unattended
by loss of life, had been fearfully destructive.
Yet, notwithstanding this severe lesson, they had
actually put down an externally-fired cylindrical
boiler-a most unmanageable and mischievous
form-without water or steam gauge, or even a
fusible plug or alarum: its sole safeguards
being a float with a stuffing-box, and a most
inefficient safety-valve weighted to sixty pounds.
At the time of our visit the steam was blowing
off furiously, so that the pressure must have
been much above 60lb., very likely nearer 100lb.
per inch. The danger was by no
diminished by the fact that the boiler was made
with lap joints, and, of course, single riveted.

means

If cylindrical boilers are to be used at high pressures, the bodies and flues ought to have the longitudinal joints welded, and each length rolled to a truly circular shape, The transverse joints ought all to be double butt joints, and the plates thick edged, on Alton's plan. As regards rolling a tube, why should not complete bodies and flues be rolled at once? It is only a question of size of machinery and careful design. The demand for such boilers could not fail to be large.

Described on page 462.

inch, the very great superiority of such a material to iron, only capable of bearing 20 to 22 tons, needs no lengthened comments. The use of steel for boilers has been much restricted by the general impression that the steel must be drilled and not punched. That drilling is, per se, better than punching we feel convinced, but is it not just as superior for iron as steel, if the latter be afterwards annealed?

With regard to punching steel plates, we have before us the results of a very careful set of experiments carried out by the Bolton Iron and Steel Company, and, from their important bearing on the question of increased safety with high pressure boilers, we give the tabulated results. Six pieces 23in. long by 7in. broad and 5-16in. thick, were cut from the one steel plate. Three of these were prepared by punching, and three by drilling, with in. holes, 14in. from centre to centre, suited for single and double riveting. In a strapping machine these were then cut to the forms shown in Figs. 1, 2, and 3.

weight. The results are given in Table I.:They were tested in a lever machine by dead

Number of Test.

Thick
ness.

Area.

TABLE I.*

Breaking Weight Weight weight per sq. in. per sq. in. on Lever. of section of section drilling. punching.

1 D. 16

0-5437

Tons cwts
19 8

35.32

0.55625

14 17

26.690

1 P.

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It will be noticed from this table that the punching has a deteriorating effect of 26-4 to 37.8 per cent., being an average of 33 per cent. Examination under a powerful glass revealed the cause of weakness, and led to the trial of annealing. In the following table are given the results of sixteen tests carried out at Chatham Dockyard. The results are furnished by Mr. Barnaby, Assistant Constructor of H. M. Navy.

It is very probable that far too little attention has been bestowed on the electrical influences brought to bear in corroding the iron of boilers, where the plates and rivets differ in amount of carbonization, &c. Bessemer steel offers a very suitable material for boilers of all kinds, and of late very considerable advance has In these experiments eight plates of steel had been made in its application. As a proof of this each four holes of 0-66in. diameter punched in it may be mentioned that up to March, 1868-them. Each plate was then cut in two, and one since which we have no return-three firms in piece of each annealed. The plates were in. Lancashire had turned out no less than 277 steel boilers, and 152 composition boilers, partially of steel.

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more efficient legislation. Let us hope also that the barbarous system of buying boilers at per ton may give way to an intelligent mode of valuation. When this is done, and the great value of pure feed-water recognized, we may expect an ex

plosion to be a rarity.

A further improvement required is the entire remodelling of "Crowner's quest-law," by which a coroner, who knows little or nothing of boilers, is assisted (?) by a jury, who usually are chosen as though it were desirable to get those who know "nothing of anything."

We want a competent tribunal to inquire into all explosions, accidents on railways, in mines, &c., whether actually fatal or not. At present we witness this absurdity, that a minor accident may occur by which one life is sacrificed, and two coroners set to work; on the other hand, an accident which maims hundreds for life will not move one coroner, unless some case of death should result. These are the abuses of a bygone age which have dragged on to the present.

ACCESSORIES TO THE MICROSCOPE. No. I.

(Illustrated on page 461.)

N connection with the polarization of light, the played an important part, and by its aid some very remarkable effects have been produced. Microscopists have not been slow in applying it to their pet instrument, and various arrangements have been invented to get the best effects, so that the objects viewed by its aid, might be seen to the NOTE. The annealed portions are shown in antique best advantage. A short time since Mr. F.

type.

2-28 x 475 2'23 × '475

22.891

It is advisable in making steel boilers to use double butt joints and double riveting, as otherwise the rivets will sheer with far less than the breaking strain of the plate; unless, indeed, the

rivets used be so large as to gain strength to the detriment of the plate. The proportions given by Mr. Henry Sharpe, of Bolton, are for 5-16in. plates, diameter of rivets, 9-16in., pitch, 1gin., double riveting; material of rivets, mild steel. With these proportions two tests gave the following excellent results, with plates taken at random from a large quantity of steel boiler plates which were being rolled to order by the Bolton Company (a), drilled plate 42-9 tons, and (b) punched ditto, 39-11 tons per square inch of net sectional area. Mr. Sharp further experimented as follows:

ad

Blankley brought before the notice of the Fellows of the Royal Microscopical Society, two forms of selenite stages, which possess two great vantages: first, simplicity of construction; and secondly, the ease with which they can be worked. It may not be known to all our readers that different thicknesses of selenite give different colours, and that the structure of some objects can be seen much better with one colour than with another. It will therefore at once be seen how desirable it is to view each object under every tint, so that the best effect may be secured.

On

Fig. 1 consists of a small brass stage, 3in. long and 14in. wide, in the centre of which is an the under part of the stage is a dovetail groove, aperture through which the object is viewed. into which is fitted a brass slide containing three or four selenites, which work as freely as the inA small spring stops the vestigator may desire. slide when the selenite is immediately under the aperture.

A punch of 11-16in. was used; first, in the ordinary way, with a bed in. bare, producing the hole shown in Fig. 4; then a bed, in. in diameter was used, giving the result shown in Fig. 5. The plates were dressed to the form shown in consists of a brass stage of similar dimensions to Fig. 2 represents the compound stage, which Fig. 6. When tested, which was done without an: the one just described; and, in addition to the nealing, the taper-holed plates gave an average of brass slide, has a revolving diaphragm with three 32-527 tons per square inch of net sectional area; the plates with straight holes, 26-004 tons. These selenites, each made to rotate, and a clear taper holes must offer advantages to riveting up. aperture, so that the object may be viewed with a single film if desired. It is certain that the desire for economy will is much larger than those in the small one, and is In this stage each selenite lead to the more extensive adoption of high pres-marked in quarters, so that the colours obtained sures, heated feed-water, and the super-heating of steam. As regards the heating of feed-water, may be registered and turned to at any time. we may notice

To increase the variety of colours and tints, right angle of the positive axis of those on the rotate each selenite until their cleavage is at the

slide.

"Green's Economizer" as a very efficient apparatus. Its chief peculiarity, as is well known, consists in the scrapers-which are very slowly moved up and down by simple gearing -to clear off the soot from the pipes through The positive axis of each selenite in the diawhich the feed is passed. By this clearance the phragm is marked coincident with those in the pipes are kept efficient in absorbing heat. Very slide. By working each film as thus described, considerable saving of fuel has been effected by and can be recorded for further reference. It will twenty-eight tints and colours will be obtained, the use of this apparatus. Waters's heater is ex-be observed that the whole of the changes are ceedingly suitable for non-condensing engines. obtained without moving the stage or taking the It possesses the advantage of thoroughly heating object out of the field or focus, thus saving much the water to the boiling point, and also of causing time and trouble. They are made by Mr. Swift, the deposit of its earthy matters as mud in the heater. With the increase of pressure, the fre- 128, City-road, London, who is preparing a comquency and destructiveness of boiler explosions plete list of changes that can be effected by them.

will increase unless efficient means be taken to combat the dangers spoken of.

Any one who will read the reports of any of the very excellent boiler associations will be convinced that, if boilers were all well made to begin with, as regards workmanship, design, and material, well mounted with efficient duplicate

safety-valves (locked), water-gauges, alarums, steam-gauges, and fusible-plugs, and finally, properly inspected, explosions would be few and far between. It is to be hoped that the Bill on this subject, introduced by the hon. member for Dudley, may either become law or lead to even

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organized food, either animal or vegetable. Cert animals require animal food, others can live with out that; but some can maintain life without a least food derived from the vegetable kingdom that vegetable life and growth require the presets Following down the scale of organization, we fod of matter arranged at least into binary compouni Vegetable tissues are made up of carbon, hydroge oxygen, and nitrogen, but, so far as known, tões elements are always obtained by plants from matt organized or arranged in compounds such as ce bonic acid, ammonia, &c.* These compounds m be, and at present are, in part derived from the animal kingdom, though not necessarily so, for the result from the breaking down of vegetable mate and may be naturally produced by union of the elements.

Although the animal kingdom cannot be me tained without vegetable food, the vegetable r dom may be without animal food; and althos vegetable life and growth cannot be maintai without matter arranged at least into binary c pounds, these compounds which serve as food plant-life can be formed and maintained with the aid of animal or vegetable matter. The an kingdom is then essentially primarily supplied: food from the vegetable kingdom, and this, in from binary and higher compounds. The com compounds, chemistry teaches us, are formed i union of simpler ones, and the simplest by union of elementary atoms.

These seem to be universal laws, to which 1 are no known exceptions. Food is essential to the growth of all organi Growth being an increase of the elements of wi a body is composed, in certain definite proport and having the arrangement proper to the grow body, it is in fact a continuation of the process organization, and the food required for growth me at least be required for the first organization creation; for the food of all organisms contains a proper form their constituent elements. If crystal be placed on the solution from which it was formed, it will, under proper conditions, grow. One condition to its growth is the supply of its proper food, which consists of the same elements, havi the same arrangement as required for its first i mation. The seed of a plant exposed to moisture absorbs water, and sap or food is formed from the material stored up in the seed which had been separated from the watery portion of the sap coutained in the parent plant; when its supply of matter, which by the addition of water serves as food, is exhausted, more is supplied from the surrounding air and soil. Like the crystal, so lon as its proper food is not furnished, the germ of the seed remains stationary; and when again, unde through the action of the organizing forces proper conditions, supplied with constituent matt nature, it grows. Animal tissues grow by mea a supply of blood, the composition of which d in different kinds of animals, but is essentially a same solution as the blood of the parent from s the germs or eggs of each were formed. I but that must be present. these cases it is not necessary that the solution the food should contain only the constituent mat

stituent matter must be to a certain extent It is, moreover, important to notice that this o viously organized. This may, perhaps, be be understood if we notice first the formation of t formation of all organic germs. Crystals form crystal, which may be considered as illustrating & solutions having the organization proper to 5:

crystal; the solution must not only contain 3 elements of which the crystal is composed, but is may contain soda, chlorhydric and sulphuric the crystalline compound. For instance, a son must be arranged in molecules, correspondin

and crystals of chloride of sodium will not because the constituent elements, although p are not combined or arranged with the prop nite relation to each other. Crystals of sulas per conditions, because its elements are soda will form from such solution, uns

bined.

formed from the sap, which is the pla The pollen and seeds as well as buds of p selected from the surrounidng earth and air: matter organized in the manner peculiar to plant; it is, in fact, the germ of the plant in solutel and seeds may in a manner be said to crystala from it. The spermatic fluid and eggs of anima are formed and perfected in an analogous mental by compound molecules, separated or secreted fr the highly organized animal fluids. The format of the fluids from which these crystals, seeds, & eggs are formed, requires the presence of the fos proper to each, and it must consist of their const tuent matter properly arranged.

govern the maintenance of life by food, organ growth, the essential nature and constitution of food, the formation of the germs of organisms and the formation of chemical compounds, we seen justified in concluding that animal life is always

From what is known concerning the laws which

*It seems proper to state that this article was written before the writer had seen or heard of Professor Hus ley's lecture on "The Physical Basis of Life."

necessarily preceded by vegetable life; that this is always necessarily preceded by a certain amount of arrangement of elements into binary and more complex compounds; that the complex compounds are universally formed from simpler ones, and the simplest by union of the elementary atoms. We can thus trace back the order of creation, or evolution of living beings, to the chemical elements.

THE BEGINNING OF LIFE. ITS LOWEST FORM, AND THE SIMPLEST ORGANISMS.

In studying the creation of living organisms, if we start with any of the higher animals, and trace back the life of an individual, we find it to begin in an organized form of matter, an egg. But the egg is a complex substance, and, although some of the conditions to its formation and development into a living being are well understood, studied by itself it is difficult to understand the creation, beginning, or source, of its vital force; and, we understand from whence the force is derived, it is still difficult to see what gives direction. If we direct our attention to the vegetable seed, we meet with the same difficulties. In order that we may understand the creation of the higher organisms, it may be well to search out the lowest, and begin the study of life in its simplest form; and, that we may be able to recognize the object of our search, we should have a reasonably perfect definition of the word life, and an idea of the characteristics of living beings. A complete and perfect definition is difficult, and is not assumed to be here given; but it will be sufficient for our present purpose to say that, from the word life, we receive an impression of certain phenomena attendant upon changes which occur in organized bodies as results of their experiences of force. This definition is perhaps incomplete, but, in fact, any attempt at a perfect definition must necessarily be unsatisfactory so long as only the higher forms of life are considered. We cannot properly define a thing until the whole of it be somewhat understood. However, if we bear in mind our imperfect definition, and keep in sight the higher kinds of life which we do understand, we can search for the lowest, which we may not, and when the whole has been considered, a definition may be more satisfactory. Let us, then analyze the characteristics of the higher living beings from which we have received our first ideas of life, and learn their essential nature. By reducing these characteristics to their lowest terms, we ought to deduce an ideal lowest form of life.

The prominent phenomena which characterize living beings are 1. Organization; 2. Definite Chemical Composition; 3. Definite Form; 4. Growth; 5. Continual Change; 6. Motion; 7. Reproductive Power.

Our idea of life being mainly formed from our knowledge of these characteristics, the ideal lowest form should have them in the simplest degree. Commencing the search by considering them singly, we notice first that living bodies are organized.

According to the ordinary definition, an organism is a body consisting of organs, or mutually dependent parts having functions. The lowest organism should consist of the least number of mutually dependent parts, having functions of the simplest character.

The least mutually dependent number would be two-and, as the smallest portion of matter imaginable is called an atom, nothing less than that could be conceived as having a function; and, as the functions of two precisely similar atoms would be least contrasted, and of the simplest character, the lowest organism should consist of two equal atoms organized or arranged, so that its existence as an organism would depend upon the functional activity of each, which might consist in their mutual attraction for each other. This would be the case in a molecule consisting of two atoms of a chemical element. And, as the atoms of an elementary substance are alike, their functions would be equal.

We notice, next, that living bodies have a definite composition; they consist of definite proportions of certain elements definitely arranged. Arrangement implies relation, and would require, at least, the presence of two units. The simplest definite proportions would be equal, and as the least portion of matter is the atom, a definite compound reduced to its lowest terms should consist of two equal atoms arranged with the simplest definite relation to each

other.

parts, and again show that the lowest living things are organisms.

tain extent, result from the forces acting upon it. As the atoms of an elementary body are alike, and, subjected to the same force, vibrate alike, and the This higher view is furnished us through a knowatoms of different elements are unlike, and vibrate ledge of chemistry, which teaches that there is differently, few or many changes will be produced a mutual dependence of parts which extends to the by a given force, according as it acts upon a body molecules, and even to the ultimate atoms of all deconsisting of one or many different elements. Afinitely combined matter. A definitely chemical given force should therefore produce the least num compound consists of definite proportions of matter ber and variety of changes by combination or re- definitely arranged. For instance, albumen is comarrangement, and by mutual reactions of consti- posed of carbon, hydrogen, oxygen, and nitrogen, tuent matter and force, will be least where atoms in certain proportions, and arranged in a certain of only one element are present. manner: if either the proportion or the arrangement be destroyed, the matter no longer constitutes albumen. The several elements of which it is composed may be considered as organs performing essential functions, their mutual dependence being absolute; for, if one be removed, the compound is destroyed. Probably the presence of each atom of each element is essential to the existence of the compound, so that a molecule of albumen may be considered an organism, although not in accordance with the idea heretofore entertained. The same may be said of a molecule of water or of any other such group of atoms definitely arranged. Albumen was selected as an example, because the lowest living things revealed by the microscope cannot, by the aid of the highest magnifying power, be distinguished from mere minute particles of albumen.

Motions result from force, and the greatest variety of motion will be produced by forces acting upon the greatest number and variety of elements. Motion of the simplest character results from the action of force upon homogeneous matter.

Reproduction consists, essentially, in the generation of new bodies, and communicating to them the properties characterizing the parent, as regards both matter and its arrangement. The reproductive process should be simplest where the body to be reproduced is simplest, and we have seen that this must be the case when it consists of the least organizable quantity of one kind of matter, viz., of two atoms of one chemical element.

If we now sum up these several least require ments, we find that, from this analysis of the characteristics of living organisms, it appears that, reduced to their lowest terms, they must consist of two atoms of a chemical element arranged with the simplest definite relation to each other. This should be the beginning of the lowest form of life, and we also found this to be the lowest ideal organism. It is represented by the ultimate molecule, which may be the nucleus or beginning of a crystal of a chemical element.

The conclusion here reached by deduction will no doubt be at first regarded with astonishment, and without inductive proof it is not expected that this view can be received except by those already prepared by a knowledge of such proof; but the evidence which the writer has seen on the subject is such as to convince him that the same conclusion may be reached by other and more satisfactory methods of research. This method of first presenting the subject has, however, been selected because it seems to show, from a study of the somewhat imperfect idea of life, what is necessary to its perfection. Consideration of the subject from this stand-point first, may prepare some minds to study it thoroughly without the prejudice which might otherwise prevent; and, finally, because the building up of any structure is greatly facilitated by first perfecting a definite plan, so that the position and relation sustained by the component parts may be readily seen as soon as each is presented.

It is believed that the generalization indicated may be made and established with great advantage to the study of biology. The plan of the creation or evolution of living organisms is thereby rendered much more simple and easy of comprehension, as may perhaps be made to appear at some future time."

Whether the lowest living things can be properly called organisms, will depend upon the definition of the words organism and organ. According to the ordinary definition, an organism is a body consisting of mutually dependent parts having functions, and an organ is one of such parts. The word organ, as appears from the above quotation, has heretofore been applied only to visibly distinct parts having functions, &c., although the definition; in our standard dictionary is similar to the one given above, and has no such requirement.

The standard definition will allow of its use in the extended sense that I wish, viz., to denote any mutually dependent parts of definitely-combined matter having separate functions, whether or not the part or function be capable of demonstration to the single sense of vision. It is essential to a right understanding of scientific problems, that the terms employed should have a precise meaning. If the words organ, organism, and organized, cannot appropriately be used in connection with all definitelycombined matter, and must, on account of old associations, be restricted to such compounds as have visible distinctions of parts, then it would seem to be advisable to invent new terms which shall, in a word, or as concisely as possible, embrace all such compounds, and thereby render easy this comprehensive and general view. But if this be done, the old words left as heretofore, there is then no well-marked limit or beginning of organization, for what is visible to one, under certain circumstances, may not prove so to others, and again the limit would vary with the magnifying power used. If however, the old terms (organism, &c.) be retained and thus defined, it will still be easy to distinguish between visible and invisible organs; the invisible orgaThe ideal lowest form of life and the lowest organ-nization may be denominated primary, as it undoubtism we have found to consist of "two atoms of an edly is, to vegetable and animal organization. In my elementary substance arranged with the simplest opinion, the science of biology will at present be best definite relation to each other," and we know that facilitated by thus extending and defining the there are existing in nature such combinations of words used. The important reason for wishing matter. In a previous part-"The Order of Crea- thus clearly to define and extend their meaning is tion of Living Beings "-it was pointed out that their to collect under one general view the prominent creation could be traced back to the chemical ele- phenomena attendant upon matter arranged in defiments as its starting-point. From this lowest form nite compounds. At present certain highly-complex, of life there is a constantly-ascending scale up to definite compounds are called organisms; certain human life. From this simplest organism there is others, less complex, living things, but are not cona constantly-increasing complexity of combination sidered organisms, because not having visible and organization up to the human organism. An organs; others, nearly as complex as these last, attempt will be made to show that the phenomena are called organic, because heretofore only attendant upon changes occurring in the simpler found in organisms; others still complex, are combinations which may be called primary organ- called inorganic chemical compounds. The proisms resemble, and are in fact similar to, those minent fact connected with all these structures which are recognized as characteristic of living is, their definite composition and definite atomic beings. We shall find how perfectly they accord or molecular arrangement: and the certain and with our definition of life. regular phenomena attendant upon their experience of certain conditions are believed to be in consequence of this definite composition. This broader generalization seems to me to be useful, taking in as it does all definite combinations, and distinguishing them from amorphous, non-arranged, or, according to my view, unorganized matter. If this be done, as heretofore indicated, the beginning of the simplest organization will be where the first two atoms unite with a certain or definite relation to each other, to form a definite compound. In accordance with the foregoing views, life is conceived to be manifested by all organized matter, the kind of life depending upon the character of the organization.

Beginning the subject inductively, let us first consider organization; that being an acknowledged characteristic of at least the higher living beings, and the first one mentioned in our analysis.

The word organism has heretofore, I believe, only been applied to those compounds which have visible distinctions of parts; leaving out, among those which have not such distinctions, some which were nevertheless considered living. "The lowest living As to form, we should expect to find the lowest things are not, properly speaking, organisms at all; life, having definite form, of the greatest simplicity. for they have no distinctions of parts, no traces of Complexity of form results from complex arrange- organization "—(Herbert Spencer). Before the miments of heterogeneous elements; the greatest sim-croscope revealed its world of living beings, the plicity of form will result from the simplest arrange-general idea of organisms probably included only ment of like elements. Simple definite forms are those whose organs or distinctions of parts were found in crystals of the chemical elements, gold, visible without its use; some minute moving bodies copper, iron, sulphur, phosphorus, carbon, &c., which were no doubt by some considered living, although usually crystallize in simple cubes or octahedrons. their organs could not then be distinguished. AfterGrowth is an increase of the elements composing ward, with the aid of the microscope, their organs the body, in the proportion and having the arrange- were plainly seen, as were also myriads of other ment proper to it. The simplest requirement for organisms. With the microscope other minute growth would be the smallest equal proportions of moving bodies have been brought to view, and are one element with the simplest definite atomic now considered living, although their organs canarrangement. This might be the case in bodies not be distinguished. We have again reached a consisting of one element. point where a still higher vision is required to enable The changes occurring in a living body to a cer- us to see a mutual dependence and distinction of

Among scientific men, at the present time, the tendency is to look for the lowest organization and the beginning of life among the protean compounds; and protoplasm is the name given to what many now consider as the connecting link between inorganic matter and living organisms. It seems to me, however, that they are not searching deep enough; that protoplasm is about midway between amorphous matter and the highest organisms, and cannot profitably be considered as the beginning of life or of organization, although it may be, as the beginning of the two highest organic kingdoms-the

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vegetable and animal. I prefer to consider the diamond as one of the lowest organized forms, and with my mental vision distinctly see the beginning of organization and the conditions for life where, through cer

tain conditions of force, the first two elementary atoms are enabled to manifest their mutual attraction, and affectionately and definitely embrace.

We have, however, considered only one of the characteristics of living beings; we have still to consider, in this connection, definite chemical composition, form, growth, continual change, organic motion, and reproductive power.

Definite Composition of Organisms, and Consequent Definite Function.-Proximate analysis of the higher organisms shows them to be composed of various compounds, such as water, sugar, starch, fats, albumen, fibrin, &c., which are called proximate principles. Ultimate analysis of these proximate principles shows them to be definite chemical compounds, essentially the same in all organisms of a kind; but, to a certain extent, peculiar to each kind, either in quality or proportion.

Water is essential to the composition of all the higher organisms; each kind of organism having, within certain limits, its own peculiar, definite proportion, which is essential to its existence as an organized form.

257. Common mode of raising water from wells Although free, uncombined water is always the of inconsiderable depth. Counterbalance equals same under the same conditions, the properties of about one-half of weight to be raised, so that the organisms, formed by its combination with other bucket has to be pulled down when empty, and is substances, in great measure depend upon its pro-assisted in elevating it when full by counterbalance. portion and manner of union.

The sugars, as existing in various organisms, are more or less peculiar to each. Sugars derived from the maple, cane, grape, or beet, can usually be distinguished from each other, and from those derived from other sources, by their obvious characters. It is generally possible, by observing the flavour, to tell the source from which honey has been collected. Animal sugars, no doubt, differ, although, as yet, they are not as well understood. There is doubtless, much to be learned concerning the various kinds of sugar, but chemical examination has demonstrated that many of these different kinds have different chemical composition.

The grains of starch, from different organisms, may generally be distinguished by viewing them through a microscope: their forms being different, they have, at least, a different arrangement of These simple compounds, consisting of few elements, can, consequently, have few modifications. Water, consisting of quite simple proportions, of only two elements, is always water, and we know of only one kind of pure water. Sugar and starch, consisting of several atoms each of three elements, exist under several modifications of composition, as regards proportion and arrangement of elements.

(To be concluded next week.)

267. Robertson's hydrostatic jack. In this ram is stationary upon a hollow base, and/ 259. Reciprocating lift for wells. Top part re- cylinder with claw attached slides upon it presents horizontal wind-wheel on a shaft which pump takes the water from the hollow bar carries spiral thread. Coupling of latter allows forces it through a pipe in the ram into the ey small vibration, that it may act on one worm-wheel and so raises the latter. At the bottom of at a time. Behind worm-wheels are pulleys over there is a valve operated by a thumb-screw to which passes rope which carries bucket at each ex-back the water and lower the load as gradually tremity. In centre is vibrating tappet, against may be desired. which bucket strikes in its ascent, and which, by means of arm in step wherein spiral and shaft are supported, traverses spiral from one wheel to other, so that the bucket which has delivered water is lowered and other one raised.

260. Fairbairn's bailing-scoop, for elevating water short distances. The scoop is connected by pitman to end of a lever or of a beam of singleacting engine. Distance of lift may be altered by placing end of rod in notches shown in figure.

261. Pendulums or swinging gutters for raising water by their pendulous motions. Terminations at bottom are scoops, and at top open pipes; intermediate angles are formed with boxes (and flap valve), each connected with two branches of pipe.

262. Chain pump; lifting water by continuous circular motion. Wood or metal discs, carried by endless chain, are adapted to water-tight cylinder, and form with it a succession of buckets filled with water. Power is applied at upper wheel. timony have been discovered. M. Descloizeaux is en- leaves turn on pivots below centres; upper 263. Self-acting weir and scouring sluice. Two gaged on the study of their crystallography

Some new minerals composed of oxides of lead and an

268. Flexible water main, plan and section. T pipes of 15in. and 18in. interior diameter, having some of their joints thus formed, conduct water across the Clyde to Glasgow Water-works. Pipe are secured to strong log frames, having hinges with horizontal pivots. Frames and pipes were p together on south side of the river, and, the north end of pipe being plugged, they were hauled acros by machinery on north side, their flexible structure enabling them to follow the bed.

(To be continued.)

A NEW PHOTOMETER.-A photometer, invented by M. Nagent, is based upon the formation of a column of liquid partially opaque, which may be drawn out until the length is such that the light from an illuminating body ceases to be visible through the liquid. The length of the column, which completely obscures the light, starting from the point where the column is under examination. thinnest, gives a measure of the intensity of the light

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