546 LIQUID PARTS OF ANIMALS. 



7. When evaporated to dryness and burnt, this excrementitious 

 matter left behind it an ash, which was found (not reckoning the 

 sand) to consist of the following salts and earths in the propor- 

 tion stated :* 



Lime, . . .12 



Phosphate of lime, . 12-5 



Magnesia, ... 2 



Iron, ... 5 



Alumina with some manganese, . 14 

 Silica, ... 52 



Muriate and sulphate of potash, . 1 -2 



8. Thaer and Einhof made numerous experiments on the pu- 

 trefaction of cow-dung, both in close vessels and in the open air, 

 from which it would appear that the process resembles closely 

 the putrefaction of vegetable matter ; the oxygen of the air being 

 abundantly changed into carbonic acid.f 



III. To Vauquelin we are indebted for an analysis of the fix- 

 ed parts of the excrements of fowls, and a comparison of them 

 with the fixed parts of the food ; from which some very curious 

 consequences may be deduced. 



He found that a hen devoured in ten days 111 11 '843 grains 

 troy of oats. These contained, 



Phosphate of lime, . 126-509 grains. 

 Silica, . ,j,.i. 219-548 



346-057 



During these ten days she laid four eggs ; the shells of which 

 contained 98*779 grains phosphate of lime, and 453-417 grains 

 carbonate of lime. The excrements emitted during these ten 

 days contained 175-529 grains phosphate of lime, 58'494 grains 

 of carbonate of lime, and 185-266 grains of silica. Consequent- 

 ly, the fixed parts thrown out of the system during these ten 

 days amounted to, 



Phosphate of lime, . 274-305 grains. 

 Carbonate of lime, J.vl 511-911 

 Silica, U-i v . ftittoa 185-266 



Given out, . 971-482 

 Taken in, . 356-057 



Surplus, . 615-425 



Gehlen, iii. 321. t ^id. 295, 313. 



