OFFENSIVE GASES ARE POISONOUS. 129 



more or less poisonous. The poison may act slowly, but 

 not the less surely, and it renders a person who breathes 

 it liable to fever, cholera, consumption and other fearful 

 diseases. It is universally found that people living in 

 damp and dirty places, in houses ill-ventilated, over wet 

 cellars or on ground badly drained, are the first to be 

 attacked by cholera, dysentery, and various kinds of fever. 



406. What has this to do with agriculture ? Much. 

 It shows that the farmer who looks everywhere for manure, 

 and collects it carefully from all dirty places, of all kinds, 

 secures his own health, and improves the health and com 

 fort of his family and of his neighbors, at the same time 

 that he improves his fields and increases his crops. The 

 sweepings of rooms, the scrapings of cellars, earth that 

 has been long lying under barns or other buildings having 

 no cellars, the contents of drains, cess-pools, ditches, 

 bogs, dirty ponds, morasses and swamps, are all excellent 

 materials for the compost heap. Collected together and 

 covered with clay or loam, they become not only harmless 

 but very valuable. 



All kinds of dirt, if allowed to remain near dwelling- 

 houses, are liable to be dissolved or rendered noisome by 

 the rain, and to sink into the earth and reach and con 

 taminate the water in the well. Water thus contaminated 

 is not only nauseous to the smell and to the taste, but 

 very unwholesome. On this account the compost heap 

 should always be made at a distance from the well ; and 

 beneath every such heap there should be an abundance 

 of .clay or loam, sufficient to absorb all the valuable 

 substance that drains from the heap, and to prevent the 

 moisture from sinking into the earth. 



