2 EXPERIMENT STATION RECORD. 



the caution exercised by a thorough scientist in publishing the results 

 of his investigation. It was not for a temporary success that he was 

 striving, but for the demonstration of a ])rinciple that would bear the 

 test of subsequent study. His work bears evidence of a well-defined 

 plan, which was only interrupted by his sudden death. 



The data for each experiment had beeu calculated, summarized, 

 and filed with copious notes in a most orderly manner. In some 

 cases the mannscript had been partially prepared for publication. The 

 work of comi)leting this task has fallen into able hands, and has been 

 performed in a manner that makes the volume a most valuable contri- 

 bution to the science of animal nutrition. Although only summaries of 

 the data are given, the book covers 580 printed pages. It includes 

 experiments on the digestibility of a large number of concentrated 

 feeding stuffs and by-products, especially those obtained in the extrac- 

 tion of the volatile oil from seeds; an investigation of Stutzer's method 

 of artificial digestion, with a comparison of the results of natural and 

 artificial digestion, and a lengthy investigation, with the aid of the 

 respiration apparatus, on the formation of fat in the body from the 

 carbohydrates of the food, and on the relation of the food to the excre- 

 tion of hydrocarbons. 



Abstracts of some of these investigations are given in the present 

 number of the Eecord. 



In connection Avith the study on artificial digestion mentioned above, 

 the history of the development of the method is interesting. 



After some preliminary studies on the action of acid pepsin solution 

 on the proteids of various materials. A. Stutzer^ in 1880 proposed a 

 method for determining the digestibility of protein outside the body. 

 This consisted in digesting 2 gm. of a feeding stuft' with 250 cc. of 

 acid pepsin solution at the temperature of the body for 24 hours. He 

 believed tliat this treatment dissolved the maximum amount of protein 

 digestible. The portion dissolved he designated as the albuminoids of 

 the material, and the portion undissolved he called " nuclein." The lat- 

 ter he believed to have no nutritive value for animals. • 



Soon after this T. Pfeiffer^ compared the results of artificial digestion 

 and natural digestion with sheep. His object was to determine whether 

 the nuclein in the food was all excreted as such, or slightly changed, 

 and whether this nuclein had any nutritive value. He found that more 

 nitrogen was excreted than was accounted for by the nuclein in the 

 food. Deducting the metabolic nitrogen in the feces, there was much less 

 nitrogen than an equivalent of the nuclein. From 14 to 35 per cent of 

 the nuclein was found to be digested by the animals; and the residue 

 from pepsin digestion was found not to belong to the nuclein group at 

 all. This led Stutzer^ to revise his method and suggest the digestion 



' Jonr. Landw., 28 (1880), pp. 195, 435; 29 (1881), p. 473, 



» Jour. Laudw., 31 (1883), p. 221. 



3 ZtscLi-. physiol. Cliew,, 9 (1885), p. 211. 



