214 § 112. FEKTILIZERS. 



carbonate, that is volatilized during the process of dry- 

 ing, and which is determined in the aqueous extract of a 

 portion of the original manure, should be added to that 

 obtained by combustion with soda-lime, in order to get 

 the total nitrogen. 



e. Ammonia. — ^Determine this by the distillation of 

 15-20 grms. of the dried and ground manure, with 1 grm. 

 of freshly ignited magnesia, and water, and the estimation 

 of the ammonia in the distillate by titration (§ 47, c). 



/. Sulphur and sulphuric acid, — Determine total sul- 

 phur in the manure by fusion of 3-4 grms. of the powder 

 with potassic nitrate (§ 92). 



g. Aqueous extract of the manure. — Pour 3000 c.c. of 

 water over a second portion of 1000 grms. of the fresh 

 manure, mix the whole well togetlier, let the mixture 

 stand quietly several hours, and decant the supernatant 

 liquid. In order to wash the residue without using too 

 much water, put it in a large funnel, which is stopped in 

 the throat with asbestus, and below with a cork, press it 

 down, pour water over it, and work the whole over gently 

 with a pestle ; after a time, remove the cork, and let the 

 liquid run off, and repeat the operation until the water 

 that passes away is almost colorless. Reserve the residue 

 in the funnel for further treatment. 



Filter the whole quantity of the liquid with which the 

 fresh manure was treated through linen, make the volume 

 of the filtrate and washings up to 6000 c.c, and, if neces- 

 sary, filter again through paper. 



1* Ammonic salts. — ^Determine volatile ammonic salts 

 (ammonic carbonate) in 300-600 c.c. of the aqueous ex- 

 tract, by distilling off about 'I3 of it in the j^i'oper appa- 

 ratus (§ 47), without adding any alkali, and titrate the 

 distillate with the standard sodic solution as usual. 



Determine non-volatile ammonic salts by adding 1-2 

 grms. of freshly ignited- magnesia, or 10-15 c.c. of milk of 



