PHOSPHATE 5 07 FOOD RESTORED BY EXCREMENTS. Rl 



If the restoration be imperfect, the fertility of our fields, or of 

 the whole country, will be impaired ; but if, on the contrary, we 

 add more than we take away, the fertility will be increased. 



The importation of urine or of solid excrements from a foreign 

 land, is quite equivalent to the importation of corn and cattle. 

 All these matters, in a certain time, assume the form of corn, 

 flesh, and bones ; they pass into the bodies of men, and again as- 

 sume the same form which they originally possessed. The only 

 true loss that we experience, and that we cannot prevent, on ac- 

 count of the habits of our times, is the loss of the phosphates, 

 which man carries in his bones to the grave. The enormous 

 quantity of food, which man consumes during the sixty years of 

 his life, and every constituent of it that was derived from our 

 fields, may again be obtained and restored to them. It is quite 

 certain, that it is only in the bodies of our youth, and in those of 

 growing animals, that a certain quantity of phosphate of lime is 

 retained in the bones, and of alkaline phosphates in the blood. 

 With the exception of this extremely small proportion, in com- 

 parison with the actual quantity existing in the food, all the salts 

 with alkaline bases, and all the phosphates of lime and magne- 

 sia, which animals daily consume in their food, — in fact, there- 

 fore, all the inorganic ingredients of the food, — are again obtained 

 in the solid and liquid excrements. Without even instituting an 

 analysis of these excrements, we can with ease indicate their 

 quantity and their nature, and we can estimate their composition. 

 We furnish to a horse daily 4£ lbs. of oats and 15 lbs. of hay ; 

 the oats yield 4 per cent., the hay 9 per cent, of ashes ; attd from 

 these data we calculate, that the daily excrements of the horse 

 must contain 21 ounces of inorganic materials, which have been 

 obtained from our fields. The analyses of the ashes of hay and 

 of oats inform us in per centage how much silica, alkalies *-£»d 

 phosphates are contained in them.* 



• The ashes of oats contain, according to Saussure — 



In 100 parts. 

 Soluble salts with alkaline bases - - 16 

 Phosphate of lime - - - - - 24 

 Silica 60 



Th« Mhes of hay contain, according to Haidlen — 



