August U, 190S] 



SCIENCE 



217 



0)1 the Behavior of Lecithin tvith Bile Salts and 

 the Occurrence of Lecithin in Bile: 3. H. Lonq 

 and Feakk Gephart. 



The occurrence of lecithin in bile is still a dis- 

 puted question. From work on the bile of the 

 polar bear Hammarsten concluded some years ago 

 that lecithin is a normal constituent of the bile 

 of this animal. The evidence was indirect, as 

 the presence of the lecithin wa5 inferred from 

 the recognition of certain decomposition products. 

 Failing to effect a separation ourselves, we have 

 attempted to show the presence of lecithin in ox 

 bile in other ways. In preparing pure bile salts, 

 in this case a mixtui'e of taiirocholate and glyco- 

 cholate of sodium, it was found that they con- 

 tained about 0.3 per cent, of phosphorus. This 

 observation has been frequently made and is one 

 of the grounds on which the lecithin content is 

 assumed. We have determined the sulphur, the 

 nitrogen, the phosphorus and the optical rotation 

 of these salts, and the results may be best ex- 

 plained by assuming the presence of about 7.5 

 per cent, of the lecithin body. For various rea- 

 sons, however, the calculation can not be exact. 

 We have determined the extent of the solvent 

 action of bile salts on lecithin and find that 100 

 parts of the former will dissolve almost exactly 

 80 parts of the latter to yield a clear solution. 

 This solvent action is much hastened by the 

 presence of many inorganic salts, but the weight 

 dissolved is not increased. We have found the 

 optical rotation of a mixture made in the above 

 proportions, the results of which justify the 

 figures given some years ago by XJlpiana for the 

 rotation of egg lecithin, assuming that in our 

 mixture the one active body does not interfere 

 with the other. We believe this assumption to be 

 correct, or, in other words, that the solution of 

 the lecithin in the bile salt solution is a phj'sical 

 rather than a chemical phenomenon. We have 

 carried out some experiments to show the extent 

 to which these artificial mixtures of lecithin and 

 bile salts may be separated from each other, and 

 conclude from the results found that there is but 

 little prospect that the very small amount of the 

 lecithin which may occur in bile may be actually 

 separated and identified as such. 



Some Experimental Studies on Indigestible Car- 

 lohydrates: Victor C. Mtebs. (From the 

 Sheffield Laboratory of Physiological Chem- 

 istry, Yale University.) 



The purpose of this investigation was to de- 

 termine quantitatively the digestibility of lee- 



land moss, Cetraria islandica, in man. In three 

 experiments on two different individuals, the raw 

 cetraria carbohydrate was almost completely re- 

 covered in the stools. In one experiment in which 

 the material was thoroughly boiled there seemed 

 to be a slight utilization. Two experiments re- 

 cently made by Mr. IMacArthur, in this labora- 

 tory, with one of the isolated carbohydrates, 

 lichenin, indicate the possibility of its complete 

 utilization. This is certainly different from what 

 beaker digestions would lead us to expect. It is 

 hoped by further investigation the coming year to 

 finally solve this problem. 



The Effect of Phytic Acid and its Salts on 

 Plants: Oswald Scheeinee and M. X. Sul- 

 livan. 



Wheat seedlings growing in soil were found to 

 afl'ect the fertility of this soil in such a way 

 that the seedling crop of wheat was retarded in 

 growth. Among the products of germination 

 there was found by Patten and Hart's method a 

 small amount of phytic acid or anhydro-oxymethy- 

 lene diphosphoric acid. Accordingly, this acid 

 and its salt were tested as to their effect on 

 wheat. Phytic acid was found to be toxic to 

 wheat in solutions as weak as five parts per 

 million. Its sodium and potassium salts, on the 

 contrary, were decidedly beneficial. The toxicity 

 of the free acid is greater than the toxicity of 

 phosphoric acid containing the same amount of 

 P2O5. The increase in transpiration and green 

 weight in solutions of the potassium and sodium 

 phytinate is about the same as the increase given 

 by di-potassium and di-sodium phosphate con- 

 taining the same amount of P2O5. Phytic acid 

 and its salts appear to play an important rOle 

 in plant synthesis. 



A Stitdy of the Forms of Nitrogen in the Urine 

 of Eerljivora receiving 'Nutrients from a Single 

 Plant Source: E. V. McCollum and E. B. 

 Hart. 



Three lots of calves have been fed for more 

 than a year with rations derived from a single 

 plant source. These rations were respectively 

 corn, wheat and oats, and their products. A 

 standard lot received a mixture of the above 

 grains and their products. The object of the ex- 

 periment is to study biologically the value of 

 proteids from different plants for the nutrition of 

 animals. An extended study is being made of 

 the metabolism of these animals, but most of the 

 data are as yet too incomplete to be reported. Of 

 the total nitrogen digested, the following per 

 cent, was eliminated in the urine: 



