for general cleansing purposes, but is seldom a source of drinking supply, though when collected properly and well stored it is a good, safe water, though rather unpalatable to those accustomed to our harder waters.

Considering first the surface or shallow well as to its sources of supply, character of its water and the means by which matters of dangerous character may gain entry. By a surface well is meant one which depends for its supply on the rain and melted snow waters which are absorbed by the soil and which seep down into the subsoil till held by the first impermeable stratum of rock or hardpan. Along this stratum the water oozes gradually or may even flow in small streams, flowing usually in the direction of the general dip or fall of the country. While these wells are called surface or shallow wells, such wells may,

so far as actual depth is concerned, vary from four to five up to several hundred feet, all depending on depth of water retaining stratum. If this impermeable stratum makes its way to surface by a fall in the ground (gradually or abruptly) then such water flows out on surface to form a surface spring, or form a marshy spot. The source of supply here, then, is the ground water, which rises and falls with the amount of rainfall, the porosity of the soil and the dip of the ground at the point at which water bearing layer is tapped. Such a well practically constitutes a drainage basin for the ground or subsoil water of its neighborhood as distinct from the surface run-off water. The rain, in soaking into the soil from the surface, naturally carries with it in solution and suspension considerable soluble material from the air and soil, and many minute particles. Most of the particles become gradually filtered out in its passage and the dissolved matters much altered and purified as the soil has marked purifying properties, 6 w.I. (1)

especially if not over-worked, when it becomes 'soured or choked' and unable to effect purification. The general character of the water in a surface well depends on many factors, such as character of the soil, whether sand, clay, gravel, rock, etc.; the amount of protection of well openings; the amount of water used, etc., but from the health viewpoint much more depends upon the character of soil in the drainage area of such well as regards the presence of human or animal wastes, vegetable or plant decomposing material, or of deleterious mineral substances, these being stated in order of their importance. Practically the only effects produced by ordinary mineral, or vegetable matter (undergoing decomposition) are to induce some gastro-intestinal disturbance with diarrhoea, but with the entry of animal waste, and especially human excretions, there is added the danger of production of special diseases like typhoid fever, acute dysentery, cholera etc., because the germs of these diseases are given off in the excreta, hence if gaining entry to water can be carried to others. If the human or animal wastes carried thus into water do not contain these special germs, then nothing more serious will be produced by such material than by presence of equal amounts of decomposing vegetable

matter. Thus in my work I have often been told when condemning a well as containing human or animál wastes that the well was in use before I was born, that no illness had ever been traced to the water and hence there was no valid reason for condemning the well and stopping use of the water. I can only say that such people have been lucky, for once there is human waste gaining entry there is the possibility of introduction of the special disease-producing germs.

Now in all works on sanitation classifying sources of water supply as to disease carrying possibilities, the surface well is classed as potentially dangerous. Why is this? Surface well water may be water as good and safe as any other natural water. When our country was younger such waters were reasonably safe, but with longer settlement and a poor or indifferent idea of house sanitation we have allowed the drainage area of many of our wells to become polluted from human or animal waste, or have been so indifferent in protection of the well opening as to allow such pollution to gain entry directly through the well mouth.

During the past few years I have had an opportunity of examination and analysis of nearly 1,000 farm, village and cheese factory water supplies and I find that on an average two-thirds of these supplies show more or less pollution with animal or human waste material-surely a very poor record. Critics may say, and to a certain extent the criticism has weight, that I only have had the

suspicious wells called to my attention. Still, in several systematic investigations of the well waters of certain villages, and of cheese factory waters of certain districts, the two-third ratio of polluted samples holds good, in fact, in some cases, the

Typical unsanitary well. The leaks in the top and around the mouth
of the well allow polluting matter to enter. The rough masonry
within the well makes contamination through the soil an easy
matter. The double bucket handled by the chain and tipped by
hand cause gross contamination by the germs of typhoid fever.

pollution reaches a higher figure. Thus, in a very recent examination in one small village with 14 well waters, but three were found not polluted, i. e., nearly 80 per cent. were infected with bacteria of human or animal excreta.

Now, what are the sanitary faults one finds leading to such a percentage of polluted wells? These I will now point out, but not in order of frequency nor importance.

(a) Mouth of wells not elevated above surrounding soil, in fact in some cases actually lying lower. The result of this, that the surface run-off water makes its way directly into well, carrying with it any waste substances present on soil

(b) Wells not properly curbed or protected for upper 4 or 5 feet. The result is practically the same as when mouth of well is not elevated, for if the upper 4 or 5 feet are not made water tight the well is an excellent drainage pit for surrounding surface water, and if soil happens to become contaminated, such contaminated material must make its way into well and with it worms, insects and small animals.

(c) Well mouth not properly covered so that dust and surface dirt, twigs, leaves, etc., can fall into the well; or water pumped up carelessly runs back in again, carrying such substances in. Through lack of covering or improper curbing frogs, mice, and even larger animals gain entry and contaminate the water. The

drips from pump should always be carried outside the well curbing.

(d) Lack of cleanliness of surface soil in neighborhood of well, e. g., such things as throwing slop water near the well, allowing accumulation of manure or house wastes nearby. It is remarkable how careless many are in these points and also such as watering animals right over or very near well mouth and allowing their droppings to lie about.

(e) Wells may be situated too near to drains or privies that leak owing to improper construction, or too near stables, manure piles or pig pens, so that the soakage from these, gradually seeping through soil, makes its way into well and thus contaminates the water.

In villages the most danger of pollution is usually from drains and privies, both of which are often improperly constructed and frequently much neglected, so that seepage from them to neighboring wells is but a matter of time, as the

Geological formation favorable to the obtaining of water by means of artesian wells.

accumulating decomposing matter gradually sours or chokes the soil and checks its purifying action.

In cheese factories and creameries the drainage is most common source of trouble to the water supply.

Thus taking the average surface well, the main sources of contamination that I have found have been no elevation of mouth, lack of curbing, improper covering and accumulation of waste material on surface soil within 20 or 30 feet of well opening, all tending towards the same end, viz., the direct or indirect entrance either through the top or upper few feet of well pit of the surface contaminated water or contamination of drainage area of a well.

I have spent considerable time on the surface well because its troubles and their causes are practically those of the other sources of water supply, so that the details of these troubles need not be again gone into. Considering next the