Obsevcations on Liebig's " Organic Chemistry.*' 135 



llie carbonate, it should be best to alter it for some mineral 

 acid in the winter. If needed to be kept over, some of the 

 methods before recommended should be adopted to fix the 

 ammonia by mineral acids. Urine of all descriptions should be 

 separated I'rom the solid excrements and kept by itself, and 

 either washed into the soil as speedily as possible, or the salts of 

 ammonia fixed. 



The ammonia in the solid excrements, or when they cannot 

 be kept separate, should be preserved by allowing as little 

 evaporation as possible ; the air may be admitted without 

 the heat of the sun, and the dung heap should be covered with 

 some substance that would absorb the ammonia and carbonic 

 acid, and not hurt the manure. Quicklime is the very worst 

 that could be applied ; the insoluble carbonate of lime is formed 

 and the ammonia set free ; most of the salts of lime are insoluble ; 

 the gypsum itself requires a great deal of water. Charcoal of 

 wood in small powder, not large pieces, should be the very best; 

 it absorbs the carbonate of ammonia ; it will help the decom- 

 position of the charcoal, which is difficult, and the charcoal 

 always contains less or more of potash. A covering of loamy 

 earth a few inches thick, moist, not wet, should retain the most 

 of the volatile substances, and may be put above the charcoal 

 powder, or by itself without any. If the charcoal is in large 

 pieces, it absorbs the ammonia and carbonic acid of the dung, 

 and even the soluble substances, and does not give them off 

 readily. I have seen in my practice one cart of street ashes, 

 which contains mineral coal in the state of charcoal, mixed with 

 four or six carts of cow-dung in the winter; and when it came 

 to be put on in the spring, in place of the rich black manure 

 expected, we had only so much dry straw ; nor did the mass 

 when applied to the ground produce much more effect than 

 ashes would have done. The ashes are too often in the state of 

 large cinders, which absorb like a sponge; the remains of do- 

 mestic fires should be well sifted, and nothing but the powdery 

 dust retained, which will be valuable from the potash generally 

 contained in the slate of carbonates and sulphates, and any thing 

 it absorbs will be speedily given out. The night-soil, if kept by 

 itself, is of much more value, incomparably more than the whole 

 heap of cinders, &c., mixed. Much good manure is lost in this 

 way ; the night-soil, urine, soapsuds, &c., should be carefully kept 

 separate from the ashes : it is like throwing them to waste, to allow 

 the cinders to absorb them. Unboiled bones are best, as they 

 contain most gelatine ; and, if present effect is wanted, they 

 should be ground small and spread thin. Some have fancied, 

 when they found roots clustered round whole bones, that it was 

 for the nourishment they contained ; but how will the bone give 

 off nourishment till fermented, which will be very sparingly from 



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