1T8 ON MANURE. 



The nature of the fixed ingredients in the excrements varies 

 according to the food. If we feed a cow on mangel-wurzel, or 

 potatoes, without hay or barley straw, its solid excrements will 

 not contain silica, but they will contain phosphates of lime and 

 magnesia, and the liquid excrements will contain carbonates of 

 potash and soda, and also compounds of these bases with inorganic 

 acids. If the fodder or food yield, on incineration, ashes contain- 

 ing soluble alkaline phosphates (such as bread, meal, all kinds 

 of seeds and flesh), we obtain from the animal fed upon these, 

 urine in which the alkaline phosphates exist. But if the ashes 

 of the food (such as hay, turnips, and potatoes), do not contain 

 any soluble phosphate of the alkalies, but only insoluble earthy 

 phosphates, then, the urine is free from the alkaline phosphates, 

 and the fasces are found to contain the earthy phosphates. The 

 urine of men and of animals subsisting upon flesh and grain con. 

 tains alkaline phosphates ; while that of animals living wholly 

 upon grass is destitute of these salts. The analyses of human 

 excrements,* those of birds living upon fish (guano), and of 



In 100 parts. 

 Phosphate of lime - - - 161 



Verphosphate of lime - - - 5 



Lime --.---- 2'7 

 Magnesia --.--. 8*6 



Sulphate of soda - - - - 1*2 



" potash - - - 22 



Chloride of potassium - - 1'3 



Carbonate of soda - - - - 1-1 



" potash - - 0'9 



Silica 60-6 



Loss 08 



* According to the analysis of Berzelius, 1000 parts of human urine 

 contain — 



1000 parts of 1000 parts of 

 Urine. the residue. 



Urea 3010 44'39 



Free lactic acid, lactate of ammonia, and} 



animal matters not separable from >x 714 25.5S 



them - « - - - - > 



Uric acid - - - - - 1 Oj 149 



Mucus of the bladder - - » 32 048 



Sulphate of potash - - - 371 554 



" soda 316 4-72 



