at all, for it chills the stomach, and retards, and sometimes arrests digestion. The colder the water, the more likely it is to do this.

Brook streams which have the appearance of purity, are not always safe to drink from, in consequence of the possible presence of dangerous animalculæ; many instances of frogs, evets, and worms, in the stomach have occurred in consequence of want of care in this particular. Those having their sources or channels near marshes, frogponds, hog-pastures, sess-pools, distilleries, poultry-yards, slaughter. houses, and saw-mills, may with good reason be avoided. Pedestrians, travellers, and sportsmen, when overtaken with thirst, should look for some farm-house, and regale themselves with a bowl of milk. rather than suck in the waters of an unknown brook. Everywhere that good milk can be obtained, it may safely be regarded as the most wholesome and nutritious drink.

The Atmosphere we Live in.

Fig. 81.

It is estimated that each individual takes into his lungs annually about 800 pounds of air, and if the reader has observed in the preceding essays the amount of food and drink consumed every year by one person, it will be discovered that the aggregate amount of air, liquid, and substantial food received per year, by only one member of the human family, amounts in the aggregate to about one and one-half tons.

The value of the air in nourishing the human system may be in a measure appreciated, when we consider what it may do in promoting the growth of a tree. Read the following narrative of an experiment, and the comments of the narrator: "Two hundred pounds of earth were dried in an oven, and afterward put into a large earthen vessel; the earth was then moistened with rain-water, and a willow-tree, weighing five pounds, was placed therein. During the space of five years, the earth was carefully watered with rain-water or pure water. The willow grew and flourished, and to prevent the earth from being mixed with fresh earth, or being blown upon it by the winds, it was covered with a metal plate full of minute holes,

which would exclude all but air from getting access to the earth below it. After growing in the earth for five years, the tree was removed, and on being weighed, was found to have gained 165 pounds, as it now weighed 170 pounds, and this estimate did not include the weight of the leaves, or dead branches, which in five years fell from the tree. Now came the application of a test. Was this all obtained from the earth? It had not sensibly diminished, but in order to make the experiment conclusive, it was again dried in an oven and put in the balance. Astounding was the result; the earth weighed only two ounces less than it did when the willow was planted in it! Yet, the tree had gained 165 pounds. Manifestly then, the wood thus gained in this space of time, was not obtained from the earth; we are, therefore, compelled to repeat our question, where did the wood come from?" We are left with only two alternatives the water with which it was refreshed, or the air in which it lived. It can be clearly shown that it was not due to the water; we are consequently unable to resist the wonderful conclusion-it was derived from the air."

If air can make a tree, it can make or unmake man, according to its quality, for the lungs of the former (its leaves) are not so perfectly constructed for respiration as those of the latter; nor is its bark so pervious to the air as the skin which envelops the human body; and before the conclusion of this essay, I shall show to the reader that many derangements of the blood and nervous system arise from impure and unwholesome air.

As my views with regard to the influence of air upon the human system are somewhat peculiar, and a proper understanding of them necessary to aid the reader in readily comprehending many important points in subsequent pages of this work, I shall subserve both the purposes of this chapter, and many which are to follow, by a general treatise on the nature and effects of this wonderful element. Air is composed of 78 per cent. nitrogen, 21 per cent. oxygen, or electricity, nearly 1 per cent. of carbonic acid gas, and more or less vapor of water, according to its temperature. I am not alone in believing that oxygen is identical, or nearly so, with electricity; but if I were, my opinion would remain unchanged until some philosophical argument could be adduced to show the contrary. The origin and real nature of both are unknown, but certain it is, their effects are similar, and whatever difference is observable, may be occasioned by its com

!

bination with other substances, for, according to generally received opinion, "Nature never presents it solitary." Still this view of the subject is not vital to the theory I am about to advance, for it is now universally admitted by scientific men, that electricity permeates every thing-the air around and above us, as well as the earth beneath our feet.

The quantity of electricity diffused in the air, exerts a potential influence on the health of man, and an excess of the element in the atmosphere is as injurious as a moiety. In dry and pleasant weather, the atmosphere usually possesses its normal share of elec tricity, but in rainy weather, it contains too much, and this remark is made with a full knowledge of the views to the contrary of some modern scientists. A popular writer and lecturer has undertaken to prove that the atmosphere is usually more negative in damp, or wet weather, than when it is dry or pleasant, and that the reason smoke so often descends when the air is filled with mists and rain, is because the smoke is positively charged with electricity, and the atmosphere, more negative than usual, attracts it, whereas usually, in dry weather, the air is positive, and repels it upon the well-known principle that two positives, or two negatives repel each other. Now, the generally accepted theory concerning the ascension and descension of smoke is, that it depends upon the density or rarity of the atmosphere. Smoke is composed of light carbonaceous particles and when the air is dry and dense, it naturally rises above it. When it is wet and rainy, the presence of so much hydrogen (the lightest of any known substance) renders the air lighter, and often so light as to cause the smoke to descend because of its greater weight. It is said in attempting to controvert this established theory, that smoke has been seen to fall when the barometer indicated more than half a degree above inean density; but this may have been owing to some local influence upon the barometer which did not affect the atmosphere when the smoke was observed to descend; or, it may have resulted from a defect in the instrument, or, still further, the smoke may have been influenced by local currents of air. But how is it proved that smoke is positively charged with electricity? The writer referred to says it is so charged by combustion." How can this be, when smoke is only produced by fire in which combustion is incomplete? Let this question of smoke, however, "end in smoke," for it is not material, only in so far as its upward or downward

movement is instanced to show the electrical condition of the atmos phere. I believe it is not questioned that the air is more dense in dry than in wet weather, and it only remains for me to show that the atmosphere is more electrical on a wet day than it is on a dry one. To do this, it simply seems necessary to point to the effects observed upon telegraphic wires. It is only on cloudy, wet, or rainy days that telegraphic operators suffer much inconvenience from atmospheric Fig. 82.

electricity, and when such weather prevails, they are sometimes knocked down by currents gathered from the atmosphere. Frequently they are compelled to suspend operations during a thunderstorm. Then, too, does not the lurid lightning, with its voice of thunder, often tell us of the greater presence of electricity when the sky is cloudy and the air loaded with vapor? Victor Hugo, in describing an equinoctial storm, says "The magnetic intensity

manifests itself by what might be called a fiery humor in the ses Fire issues from the waves; electric air-phosphoric water. The sailors feel a strange lassitude. This time is particularly perilous for iron vessels; their hulls are then liable to produce variations of the compass, leading them to destruction. The steamer Iowa perished from this cause." When this undue presence of positive electricity exists, there are, undoubtedly, currents of negative electricity moving about to some extent, and it is the approach of positive and nega tive currents toward each other which causes the lightning flash, and the atmospheric concussion which conveys to the air the sound of thunder. But if the atmosphere, as a whole, were more negative, positive currents would not traverse the telegraphic wires, but would be absorbed or taken up instead of moving in accumulated bodies toward the operator's instruments; and if the air near the earth's surface were all negative, and that far above it all positive, then would occur a constant equalization, or blending of the two opposite forces without the violent hurling of lightning balls, whose movements are observed and mutterings heard during a thunderstorm.

I, therefore, repeat the proposition, that the air in dry and pleasant weather usually possesses the electrical element to a wholesome extent, while during wet and rainy weather, it contains an excess. When the weather is fair, the human system is relatively in a positive, and the air in a negative condition; that is, the former possesses more electricity than the latter. The result produced by this disparity between the body and the element which surrounds it, is a constant radiation from the former, or, in other words, a contin ual flowing off of the electrical element into the atmosphere, as represented in Figure 33. It is well known to physiologists, that when the pores of the skin are in a healthy condition, there is an incessant discharge from the skin of what is termed insensible perspiration; but nothing is said of the motive power by which the effete particles of the system are thus so wonderfully carried off. Now, if a doctor should retire at night with his garden strewn with filth and rubbish, and on arising in the morning should find the whole mass emptied into the street, he would naturally enough inquire who or what had removed it. Surely dead and waste matter could not remove itself. Strange it is, then, that the astute professors of anatomy and physiology have never thought to ask them.