184 EXPERIMENT STATION KECORL). 



cated that an accurately graduated sjiiiidle cau be depended upon for 

 determining- the specific gravity if the temperature is carefully con- 

 trolk'd. No modifications of present methods were suggested l)y the 

 reporter or adopted by the convention. On motion of H. A. Huston, 

 the scope of the work was widened to include distilled liquors. 



Feeding stuf.s.— The leiwrt on cattle foods was submitted by H. J. 

 Patterson, and Avas devoted principally to an account of investigations 

 of methods of determining moisture, drying the ether extract, com- 

 parison of the 1.25 and 2.5 solutions for fiber determination, and the 

 separation of the different compounds of the nitrogen-free extract. The 

 following method of determining fiber was also investigated: Two 

 grams of substance was treated with 200 cc. of 1 per cent hydrochloric 

 acid for 2 hours in a tightly corked flask kept in a water bath at a tem- 

 perature of 95 to 98° C, shaking every 10 minutes. After filtering 

 and washing, the same- procedure with 1 per cent alkali was carried out. 



The recommendation of the reporter that the use of a 2.5 per cent 

 acid and alkali .solution be abandoned was adopted by the Association. 

 It was further recommended that the digestion in closed flasks, as 

 described above, and the direct determination of nitrogen-free extract 

 be made subjects of investigation during the coming year. 



In this connection a paioeron "A c()m])arison of methods of deter- 

 mining starch in feeding stuffs," by W. E. Rtone, was presented. This 

 paper deals with investigations of five methods of starch determina- 

 tion : (1) Sachsse's method — inversion with hydrochloric acid anci deter- 

 mination of invert sugar by Fehling's solution ; (2) Guichard's method — 

 inversion with nitric acid and polarization; (3) a modification of the 

 latter; (4) Baudry's method — inversion by means of salicylic acid and 

 polarization; and (5) precipitation of starch paste by means of barium 

 hydrate, as proposed by von Asboth. All these methods gave good 

 results Avith pure starch ; in other cases discordant and unexjjlainable 

 results were obtained, due probably to the presence of pentosans in the 

 materials examined. Xylan was treated by the different methods, and 

 in every case behaved toward the reagents like starch. The use of 

 diastase or malt infusion to separate the starch from the other sub- 

 stances which behave like it toward reagents is recommended. 



A brief paper detailing methods of separating the various constitu- 

 ents of nitrogen-free extract was read before the convention by W. H. 

 Krug. 



Dairy irroilucis. — E. H. Farrington presented a report on this subject, 

 briefly reviewing the past work of the Association and giving- an 

 account of the investigations carried out under his direction by a 

 limited number of members of the Association. The work in this line 

 was intended to cover (1) specific gravity by weight and by lactometer, 

 with careful observations of condition, of temperature, etc.; (2) deter- 

 mination of total solids, and (.'>) determination of fat by extraction of 

 dried solids with ether or other satisfactory solvent. 



