234 IIAKDY-BOOK OF nUSBANDRY. 



" open soil gives free passage to the liquids that fall upon it. In 

 " multitudes of cases the well is but a few yards or feet from a 

 '' sess-pool that receives the kitchen slops on one hand and a privy 

 *' vault on the other. Earth has a remarkable power of absorp- 

 " tion and disinfection, but this power chiefly resides in its fine 

 *' arkd impalpable portions — in the clay, and not in the coarse 

 " particles of sand. A well, distant fifty feet horizontally from 

 *' a privy vault, both in a clayey soil, the writer knows, which has 

 *' yielded excellent drinking-water for thirty years, as attested by 

 " its taste and by the fact that for that period no case of fever 

 *' occurred on the premises. The writer knows another well 

 *' similarly situated in New Haven, which furnished good water 

 *' for about five years after it was excavated, in what was until 

 " then a vacant lot, but after this interval became unpleasant in 

 *' taste, its flavor plainly suggesting the nature of its impurities. 



" In his researches on the cholera in Bavaria, in 1854, Petten- 

 " kofer traced its spread in several cases in the most indubitable 

 *' manner, to the use of water which had been in contact with the 

 " faeces of cholera patients. 



" The use of open vaults, or water-closets emptying into sess- 

 " pools, tends to fill up the soil with fecal matter. A single vault 

 *' poisons a circumscribed space around it. External to this limit 

 " the filth is destroyed by the action of the oxygen of the air, which 

 " is the great purifier. Within the limit named the animal 

 *' matters preponderate either constantly or at some period of the 

 " year. They may long remain simply disagreeable without being 

 " dangerous, and may again, of a sudden, in a way whose details 

 " have as yet escaped investigation, become the seed-bed or the 

 " nursery of the infection that breaks out in fevers and dysentery. 

 " The danger increases as the quantity of filth and the number 

 " of its receptacles increase. To cover them up does not neces- 

 " sarily remove the evil. The putrid matters soak into the soil, 

 " and move upward and downward in it with the motion of the 

 " soil water. When we have copious rains, they are carried down, 

 " perhaps, to nearly the level of the water in our wells. In the 

 " heat and drought of August these matters rise again. In the 



