134 Observations on hiehig^s *' Organic Chemistry." 



of corn is sustained ; with every pound of urine a pound of wheat 

 might be produced. The phosphates are soluble in urine, and 

 insoluble, till altered, in solid excrements. Bones, wool, hair, 

 hoofs, and horns contain nitrogen and phosphates. 100 parts 

 of dry bones (not boiled) contain 32 to 33 per cent of dry 

 gelatine ; and, calculating this at 5*28 per cent, the same quan- 

 tity as animal glue, 100 parts of bones are therefore equivalent 

 to 250 parts of urine. Bones will keep dry for 1000 years, 

 he says. They become warm when reduced to powder, and 

 the gelatine is then decomposed, but absorbed by the porous 

 bone and retained. Charcoal, in a state of powder, he considers 

 a very powerful manure on heavy soils. He quotes from Ingen- 

 housz to show that sulphuric acid, diluted with 8 or 10 times its 

 weight of water, would be an excellent manure, forming gypsum 

 with the lime in the soil. 100 parts of concentrated sulphuric 

 acid are equivalent, he states, to 176 parts of gypsum; if there 

 is potash in the soil, sulphate of potash may also be formed, or 

 soda, if any. 



On this last division of the subject, I would observe that, hav- 

 ing frequently used bones as drainage to the bottoms of flower- 

 pots to encourage fine plants, I have observed that the roots 

 refused to enter among the pieces of bones, when small and 

 fermented ; and the tips of the spongioles were of a dirty brown 

 diseased colour. I think it is probable this was owing to the 

 carbonate of ammonia, which, the professor says, is absorbed by 

 the bones, being in excess. This is probably the cause why 

 urine, when applied in dry weather, kills so many plants : it is 

 probably too strong, unless when the urine is well diluted with rain 

 or other water. Excess of food is always prejudicial, especially a 

 stimulant food, such as ammonia. When urine is put on in wet 

 weather, it seldom hurts; when put on in dry weather, it should 

 be well diluted. The uric acid being soluble may be the cause 

 of the harm partly, as putrid urine does not hurt so readily. 

 The urine should be carefully kept by itself, and applied fresh 

 to growing plants in wet weather, or in a diluted state ; when 

 the carbonate of ammonia already formed will be washed into 

 the soil with the urine by the rain, and any new carbonate 

 produced as the putrefaction proceeds will be given off to the 

 roots as formed, and both carbon and ammonia will thus be 

 given to the plant. Carbonate of ammonia should be the most 

 beneficial to plants of all the salts of ammonia, from the carbon 

 it contains. 



The urine of cows is used in great quantities here by gardeners, 

 for manuring vine borders, gooseberry bushes, cauliflowers. &c. ; 

 and they wash it into the soil by putting it on in wet weather 

 or using water. It is put on both when the plants are growing, 

 and in a dormant state in the winter: from the volatility of 



