In the matter of appendicitis, for instance, it was formerly asserted that the seed of grapes was responsible for the local inflammation, and that one could never have appendicitis if such seeds were not swallowed. This theory is to-day almost forgotten, and one eminent surgeon has asserted that the prevalence of this disease in a district depends on the calcium in the soil, since it is to that mineral that hard water is due, although this has not been substantiated. No information is to-day available by which the fitness of a soil for securing sanitary conditions of building can be determined.
Cancer and soil conditions.
In the case of cancer, however, while no final conclusions can be drawn, there is some definite indication that the soil conditions have connection with the occurrence and continued appearance of cancer. It is known that this dread disease is abnormally prevalent in certain districts of the world where topography and climate are fairly alike. For example, the entire region between the Danube and the Alps from Vienna westward and between the Jura and Alps to Geneva furnishes the highest mortality from cancer in all Europe. The subsoil is clay with a thin covering of surface soil, the hillsides draining on to level valleys with meandering watercourses that frequently inundate and supersaturate the already moist soil.
This condition seems to prevail wherever cancer is abnormally prevalent. In England, in northwestern France, and in Spain the topography described in every case accompanies a high death-rate from cancer. It is of great interest to find that in New York State the two districts that are conspicuously affected by this disease have the same topography. The Unadilla Valley and some parts of the Allegheny Valley are noted for their cancer houses, and in both localities we find the same kinds of hillsides and water-soaked valleys as in Germany and France. It has also been noted that the older geological formations are free from the disease and that an occasional inundation does not seem to be a factor. Altogether there seems to be some ground for assuming a connection between cancer and soil conditions, at any rate until scientists have determined the real cause of the disease in those localities where it is now so markedly prevalent.
Topography.
The soil, however, with its mineral characteristics, does indirectly affect the health of the householder because different kinds of rock form themselves naturally into different surface formations, some healthy and some unhealthy. For example, localities where granite rock abounds and comes near the surface are usually healthy because the surface slope is great enough to carry off all drainage water rapidly. The air therefore is dry and not influenced by the immediate vicinity of swamps. The drinking water is soft, and malarial breeding places are usually absent.
Limestone rock, on the other hand, is commonly laid down in horizontal strata, and while a succession of strata may frequently give rapid slopes, marshes are very common, existing even on the tops of the hills. The drinking water is always to be suspected as to quality because, in the first place, it is hard from absorption of lime, and in the next place, cavities and seams in the rock allow polluting material to travel for long distances.
Sandstone, being porous, may be considered a healthy foundation, and sands and gravels of all sorts are usually free from marshy land.
Gravel has always been assumed to be the healthiest soil on which a house could be built, provided the ground water reaches its highest stage three or four feet below the cellar bottom.
Sand is equally desirable except in the cases where vegetable matter has been mixed with the sand, rendering decay imminent. Water drawn from such sands in the form of springs will contain large quantities of nitrates which may lead to excessive development of vegetable life and may have on the human system the same laxative effect as comes from drinking swamp water.