114 METHODS OF ANALYSIS. 



MEAT EXTRACTS. 

 1. Preparation of Sample. Provisional. 



Liquid and semiliquid meat extracts and similar preparations should he 

 removed from the container and thoroughly mixed before sampling. In many 

 liquid preparations a sediment forms which should be carefully removed from 

 the bottom of the container and included in the sample. 



2. Moisture. Provisional. 



Follow the directions given on page 38, under " VI. General Methods," 

 employing about 2 grams of powdered preparations, about 3 grams of prepara- 

 tions of pasty consistency, or from 5 to 10 grams of liquid extracts, according 

 to the solid contents. Dry the powdered preparations directly without admix- 

 ture. Dissolve the pasty preparations in water and dry with sufficient ignited 

 asbestos or pumice stone to absorb the solution. Tin or lead dishes or Hof- 

 meister glass dishes are often convenient with samples in which the residue is 

 to be extracted for fat, as the dishes may be cut or broken and placed in the 

 extraction tube with the sample. 



3. Ash. Provisional. 



Proceed as directed on page 38, under " VI. General Methods." To pasty 

 preparations add sufficient water to effect solution and evaporate to dryness in 

 order that the solids may be distributed evenly over the bottom of the dish. 



4. Phosphoric Acid. Provisional. 



The organic matter should be destroyed by one of the methods given on 

 page 2, under " I. Fertilizers," and phosphoric acid determined by either the 

 gravimetric or volumetric molybdate method described under " I. Fertilizers," 

 on pages 3 and 4. 



5. Chlorin. Provisional. 



Determine chlorin by Volh.-ml's wetliod. (Page 23, under " III. Inorganic 

 Plant Constituents"). For ordinary purposes the solution of the ash may be 

 employed. More exact results may be obtained by the following procedure: 

 Dissolve about 1 gram of the meat extract in 20 cc of a 5 per cent solution of 

 sodium carbonate, evaporate to drynoss, and thoroughly ignite. Extract tlm 

 residue with hot water, filter, and w:ish; return filter and contents to a plati- 

 num dish and ignite. Dissolve the contents of the dish in nitric acid, add the 

 solution to the filtrate, and determine the chlorin contents as indicated above. 



6. Fat. Provisional. 



Transfer the residue from the determination of water to a continuous-extrac- 

 tion apparatus, wash any fat adhering to the dish into the tube with ether, 

 and proceed as directed on page 39, under " VI. General Methods." 



7. Nitre genous Substances, 

 (a) TOTAL NITROGEN. PROVISIONAL. 



Employ either the Kjeldahl or the Gunning method, page 5, under " I. 

 Fertilizers." 



