F00D8 ANIMAL PKODUCTION. 



777 



tion of protein, and the diminution of the chemical activity of certain 

 micro-organisms. 



Saltpeter, even when mixed with a small quantity of salt, prevents 

 for a long time the formation of hj'drogen sulphid, and. therefore, in 

 the author's opinion, is useful in pickling meat and lish. Boric acid 

 was found to be a satisfactory means of checking the growth of rod- 

 like forms and cocci. However, it did not check the growth of yeasts. 

 Borax was found to be a very active agent for checking bacterial 

 growth. Even when mixed in small quantitj^ with salt it materiall}^ 

 increased the keeping quality of the materials preserved. For other 

 reasons, however, the author does not recommend the use of borax 

 and boric acid. 



Contribution to the estimation of assimilable protein in feeding 

 stuffs, K. BuLow {Jour. Landin., J^S (1900), jVo. 1, j>P' l-S8).—l\\ 

 order to study the true digestibility of nitrogen, digestion experiments 

 were made with sheep by the usual method, and the feces were treated 

 by the Kiihn method of artificial digestion with pepsin and by the 

 Stutzer method with pepsin and trypsin. The different feeding stuffs 

 were also digested artificially by the Kiihn and Stutzer methods. The 

 effect on digestibility of rapid drying of feeding stuff's was also tested. 

 The following table summarizes the average results of the diffei'ent 

 tests: 



Digestibility of nitrogen of feeding atuffs estimated by dif event methods. 



The author's principal conclusions follow: Treating samples of feed- 

 ing stuffs and feces with pepsin solution according to Kuhn's method 

 rendered the nuiximum amount of available protein soluble. A por- 

 tion of the nitrogen remaining after such treatment is rendered soluble 

 b*^ an alkaline trypsin solution. Drying the feeding stuffs renders a 

 portion of the protein insoluble in digestive juices; therefore the dry- 

 ing of feeding stuffs before samples can be ground for analysis should 

 be conducted at a temperature not exceeding from 55 to 60° C. The 

 results of the Stutzer-Pfeiffer method of estimating the digestibility of 

 protein does not agree with the results obtained in actual experiments 

 with animals. The pepsin-trypsin method gives too high results, 



