§ 112. FAEM-YAKD MANURE. 215 



lime to the remainder of the liquid in the retort, distilling^ 

 off ^Ij of the water, collecting the ammonia in the usual 

 manner, and titrating the distillate. 



The total amount of ammonia in the aqueous extract 

 may be determined also by Schlossing's method ; evapo- 

 rate 200 c.c. of the liquid down to 50 c.c. after adding a 

 slight excess of hydrochloric acid, and proceed with this 

 concentrated solution in the usual manner (§ 47, h). 



2t Nitric acid. — To determine this in the aqueous ex- 

 tract, evaporate 500 c.c. doAvn to a small bulk, and pro- 

 ceed with this concentrated solution according to Schloss- 

 ing's method (§ 62, a). 



3. Total amount of dry substance in solution. — Evap- 

 orate the remainder of the extract to dryness in a weighed 

 platinum dish, on the water-bath, and determine the total 

 amount of matters in solution. 



4. Org^anic matter. — Ignite 3-4 grms. of this residue, 

 to determine organic and inorganic matter (§ 91), and 

 determine carbonic acid and chlorine in the ash (§ 60, e). 



5. Carbonic acid.- — ^Determine this in 2-3 grms. of the 

 residue obtained in 3 (§ 60). 



6. Nitrogen. — ^Determine this in 1 grm. of the residue 

 obtained in 3, by combustion with soda-lime (§ 85). 



7. Chlorine. — This may be partially volatilized in the 

 process of incineration ; an accurate estimation of it, there- 

 fore, requires its determination in a portion of the aqueous 

 extract itself. 100 c.c. of this maybe taken, or 0.5-1 

 grm. of the residue obtained in 3, dissolved in water. 

 Add nitric acid to the solution, in slight excess, and pre- 

 cipitate chlorine with argentic nitrate ; treat the precipi- 

 tate as directed for the case in which much organic matter 

 was present in the solution (§ 63). 



Instead of following this course, a small portion of the 

 residue obtained in 3 may be fused with potassic nitrate 

 before precipitation with argentic nitrate (§ 92). 



