AGEICULTUEAL CHEMISTEY AGEOTECHNY. 17 



the butter fat. Some results are given to show that the fat does not interfere 

 with the accuracy of the method. 



A rapid method for the determination of unsaponifiable matter in fats 

 and oils, T. M. Rectob (Abs. in Science, n. ser., 39 (1914), No. 1011, p. 952). — 

 "The sample is saponified in the usual manner and the alcoholic soap solution 

 diluted to an alcohol content of 55 per cent. The solution is then extracted with 

 light petroleum spirit, the solvent evaporated, and the residue dried in vacuo 

 and weighed." 



Method of varnish analysis, R. W. Daenee (North Dakota Sta. Paint Bui., 

 1 {1915), No. 6, pp. 108-111). — "The analysis of oil varnishes is one of great 

 difficulty, and it is almost impossible with the present methods in use (Mcll- 

 hiney's, Scott's, and Twitchel's) for separation of gum and oil to get better than 

 an approximate estimate of the ingredients in a varnish." The following 

 method is suggested for long oil varnishes : 



"Three to four gm. of varnish are spread out on an Adams filter coil which 

 has been dried and weighed along with an extractive thimble. The coils absorb 

 water rapidly, and for this reason the coils and thimble must be weighed in a 

 weighing bottle. The varnish is best weighed and added to the coil from a 

 dropping bottle. The coil is then held in the mouth of a 300 cc. weighed Erlen- 

 meyer flask, and 100 cc. of petroleum ether, 0.G7 specific gravity, added slowly. 

 A large percentage of the varnish will be washed out of the coil by this treat- 

 ment. The coil is then placed in the extraction thimble and extracted for 36 

 hours [in a Caldwell extractor with the bottom cut out], or until extraction is 

 complete, when 150 cc. of petroleum ether, 0.G7 specific gravity, is added to the 

 flask and the flask cooled to 3° C, until the gums settle and the liquid is clear. 



" The liquid containing the oils and rosin is poured ofC the gums and the flask 

 washed several times with petroleum ether and the washings added to the 

 original petroleum ether extract. The Erlenmeyer flask and thimble are then 

 dried at 105°, to constant weight. The increase in weight of the flask and 

 thimble minus the weight of the metallic driers represents the weight of hard 

 gums in the varnish. The extract from the gums is freed of the jjetroleum 

 ether, saponified with half-normal alcoholic potash, and the unsaponifiable 

 matter extracted with ether. The rosin and fatty acids are then released 

 with half-normal hydrochloric acid and extracted v\-ith ether. The acids are 

 then freed of the ether and the rosin determined by Twitchel's method." 



Some results of tests with the method are included. 



Analyses of mixed paints, E. F. Ladd and W. P. Washbubn (North Dakota 

 Sta. Paint Bui., 1 (1915), No. 6, pp. 85-108). — ^Analyses are reported and dis- 

 cussed of about 70 paints, the results being interpreted in the light of the 

 paint law of North Dakota. 



The curing of meat and meat products on the farm, K, J. Seulke (New 

 York Cornell Sta. Circ. 27 (1915), pp. 13). — This circular gives practical direc- 

 tions for keeping fresh meat, curing meat, and the preparation of meat prod- 

 ucts (sausage, lard, head-cheese, blood pudding, etc.) on the farm. 



Preliminary notes on the curing of cucumber pickles, H. N. Riley (Abs. in 

 Science, n. ser., 39 (1914), No. 1017, p. 954). — "The activities manifest in a 

 curing tank of cucumber pickles seem all to depend upon the growth of certain 

 bacteria, known as ' lactic-acid bacteria.' These seem to govern the rate of 

 fermentation, or giving ofC of gas, and the production of acid. The rate of 

 fermentation mechanically governs the rate of absorption of salt, which is also 

 influenced, to some extent, by the size of the pickle. The growth of mold and 

 yeast seems destructive, as they destroy the acid which is the principal keep- 

 ing factor in the brine." 



