FOODS — HUMAN NUTRITION. 67 



egg yolk, the experirueut being continued for periods of several mouths 

 each. 



The most common phenomena which occurred in all of the experiments was 

 that in the first period after tlie beginning of the feeding the liver of the 

 animals became filled with greater or less quantities of fatty substances. With 

 continued feeding of the same materials the fat masses in the liver not only 

 did not increase, but, on the contraiy, became gradually smaller and finally 

 disappeared entirely. 



The various fats did not protluce the same effects in the animals. Whereas, 

 according to the author, the liver disposed of sunflower seed oil, liver fat, and 

 beef tallow with considerable ease, and feeding these substances produced no 

 serious changes in the liver, feeding with egg yolk and ox brain brought about, 

 in all cases, noticeable and generally similar pathological changes in the liver, 

 which increased as the feeding periods lengthened. From this it may be con- 

 cluded that these changes were not conditioned by the fats, but rather by the 

 lipoid substances (probably those of the lecithin group) which in such cases 

 were filtrated into the liver cells, together with the neutral fat, and frequently 

 surpassed the latter in amount. 



The effect of the different fats was not the same on rabbits as on rats. This 

 difference in the behavior of the 2 species as regards the lipoid substances 

 can, the author believes, be attributed to the fact that certain anatomical 

 peculiarities of the rabbits produced certain not yet understood fermentations 

 under the influence of which toxic modiflcations are produced out of the lipoid 

 substances. In general, the changes produced when rats were fed wiih egg 

 yolk were similar to those taking place in rabbits fed with sunflower oil, 

 liver fat, and beef tallow. 



Lecithin and its significance, J. Nerking (Intenmt. Beitr. Path. w. Ther. 

 Ent(iliniiif/sstiii\ ^toffw. u. Vcrdauungskraulc, 3 {1912), No. //. pp. .'/;)5-'j61). — 

 This article is a summary of the theories regarding the role of lecithin in nutri- 

 tion and its therapeutic use. The author concludes that for the latter chemi- 

 cally pure lecithin is necessary, but that most of the preparations commercially 

 obtainable are of this character. 



The respiration calorimeter — application to the study of problems of 

 vegetable physiology, C. F. Langworthy and R. D. Milner (U. S. Dcpt. 

 Agr., Office Expt. St as. Circ. 116, pp. 3). — A brief description is given of the 

 large calorimeter used for experiments with man and of a new respiration 

 calorimeter of smaller size suitable for experiments with fruits and similar 

 products which has recently been installed. Reference is also made to a micro- 

 calorimeter for use in the experimental study of vei*y small quantities. 



Recording and controlling devices of special construction involving much that 

 is new and original have been used in the construction of the respiration 

 calorimeter designed for the study of vegetable problems, so that the instrument 

 will be very largely automatic in operation and can be operated at the same 

 time and by the same observers as are employed upon experiments with man 

 in the large calorimeter. 



The work which has been done thus far with ripening fruit has demonstrated 

 that the respiration calorimeter is fully as well suited to the study of certain 

 fundamental problems of plant life as to the study of similar problems of 

 animal life. 



The apparatus can also be used, it seems safe to conclude, in studying such 

 problems as the changes which take place when meat or chees^e or other similar 

 products are cured or ripened, and factors which influence these changes; that 

 is, problems which are of commercial interest as well as of agricultural, domes- 

 tic, and scientific importance. 



