74 



Notice of some recent additions to Chemistry. 



in combining urea with hippuric and uric acids. When nitrate of 

 urea is heated to 302® F., carbonic acid and protoxide of azote are 

 evolved, while free urea and nitrate of ammonia remain. During the 

 decomposition of the nitrate of urea, a new acid is formed (L'Institut. 

 454) crystallizing in small whitish plates, which have not been accu- 

 rately examined. 



Chemistry has become of such essential importance to the agricul- 

 turist, that any experiments upon subjects connected with his art, must 

 be viewed by him with gratification. In the choice of manures, 

 chemistry has done much, and promises still more. Those who have 

 examined the French journals, must be aware of the extensive experi- 

 ments made on this subject by Boussingault. He has examined the 

 question very extensively : — Is the proportion of azote present in a 

 manure the test of its richness ? He answers the query in the affirm- 

 ative, although he does not deny the importance which other matters 

 may possess. The following table is a selection from an extended 

 series of experiments where the figures represent the equivalent num- 

 bers, farm manure being taken as unity. ( Annales de Chim.iii. 65, N.S.) 



Farm Manure, . . . 100 

 Pease Straw, .... 22-3 



Wheat Straw, .... 166-6 



Old Wheat Straw, . . 81-6 

 Lower part of W. Straw, 97*5 

 Upper part of W. Straw, 30 



Oat Straw, 142-85 



Barley Straw 173-9 



Potato Tops, .... 72-72 



Carrot Tops, .... 47 



Pulp of Potatoes, . . 76 



Juice of Potatoes, . . 106*38 

 Dung Water, .... 67*7 



Cow Dung 125-0 



Cow Urine, 90*9 



Horse Dung, .... 72-7 



Pig Dung, 63-4 



Sheep Dung, .... 36 



Flemish Manure, . . 21 0*5 



Dry Muscle, .... 3*06 



Dry Blood, 3-69 



Animal Charcoal, . . 36*69 



Dutch Manure, .... 29*4 



Oak Leaves, in Autumn, 34 

 Poplar Leaves, in Autumn, 74*3 



Guano, 80-4 



Guano, 74*1 



Guano, 28'6 



Urine, 2*4 



Urine, 55*9 



Refinery Charcoal, ... 28 



English Charcoal, . . . 5*75 



Residue of Prussian Blue, 3062 



Sea Plants, 16-6 



Sea Plants, 16-7 



Mould, 33-3 



Great disparity exists between the different kinds of Guano accord- 

 ing to the above table, which we have fully confirmed in our experience 

 in Glasgow. We have met with Guano containing so small a per 

 centage of ammonia as 4i and as high as 15, facts which should induce 

 purchasers to cause samples to be chemically tested before concluding 

 their agreements. In the above table, the substances are supposed to 

 be in the moist state and not dried. The table is read thus : — 100 

 parts of farm manure are equivalent to 22*3 parts pease sti-aw, or 36 

 sheep dung, &c. 



