444 



SCIENCE 



[N. S. Vol. LIV. No. 1401 



Concerning tlie nature of the toxic products of 

 Bacillus botulinus: J. Eronpenbrenner and M. J. 

 SCHLESINGER. As a result of growth of Bacillus 

 botulinus on appropriate medium rich in nitrogen, 

 there can be demonstrated in the culture filtrate 

 toxic products of two kinds. One is heat resistant, 

 soluble in alcohol and acts without the incubation 

 period. This toxic product consists of ammonia 

 salts and is readily destroyed by the addition of 

 strong alkali. The other possesses the properties of 

 a true bacterial toxin. It is thermolabile, it acts 

 only after a definite period of incubation, is not 

 soluble in alcohol, has antigenic properties, and is 

 neutralized by a specific antibody. This toxin is 

 quite distinct from other bacterial toxins in that 

 (in its crude state) it is poisonous when taken by 

 mouth, in addition to being poisonous by injection, 

 as is also the case with other l>acterial toxins. 

 When purified, however, this toxin loses its toxicity 

 by mouth, while its activity by injection remains 

 miimpaired. When the fraction removed by purifi- 

 cation is reunited with the purified toxin, the mix- 

 tiire recovers its toxicity by mouth. In addition to 

 the properties already mentioned, this toxin ex- 

 hibits other characteristics unobserved in connection 

 with other bacterial toxins. For example it is not 

 digested by either pepsin or trypsin. By a proper 

 adjustment of the hydrogen ion concentration it 

 can be rendered as much as IO12 times more potent 

 than other toxins. Unlike other toxins, it must be 

 of a comparatively simple chemical composition, as 

 its molecular weight is not more than 260 with only 

 3 X 10 - 23 gms. of total nitrogen in one lethal 

 dose for a mouse of 18 gms. It appears to be the 

 most potent substance ever described. 



The internal factor in photosynthesis: H. A. 

 Spoehe. 



Comparative stability of alkyliarbituric acids as 

 determined by availability of nitrogen for fungus 

 cultures: A. W. Dox, Lester Toder, and Adelia 

 McCbea. One of the criteria of synthetic hypnotics 

 appears to be chemical stability. In the barbituric 

 acid series, hypnotic properties are confined to the 

 5, 5-dialkyl derivatives, the 5-monoalkyl derivatives 

 being physiologically inert. This difference may be 

 due to a difference in chemical stability, since the 

 monoalkyl derivatives contain a reactive hydrogen 

 which might be a point of attack for biological 

 oxidation. On this assumption, a difference should 

 be expected in the utilization of the nitrogen by 

 fungi. Cultures of Feiiicillium expansum were in- 

 oculated into a synthetic medium containing M/50 

 nitrogen in the fonn of alkylbarbiturie acid. The 



series included eight mono- and seventeen di-alkyl- 

 barbiturio acids. A slight growth, far from normal, 

 was obtained on all of the mono-alkyl derivatives, 

 whereas the di-alkyl derivatives gave only germina- 

 tion similar to the controls without nitrogen. 



The chemical composition of the body fluids of 

 the sea-lion: R. B. Swain, and N. W. Eakestraw. 



The molecular weight and transition point of 

 gelatin: E. T. Oakes, and C. E. Davis. 



The non-protein nitrogen of the hen 's egg : J. S. 

 Hepburn. 



Biochemical studies of insectivorous plants: J. S. 

 Hepburn, E. Q. St. John, and Frank M. Jones. 



Studies an the digestibility of proteins in vitro. 

 III. On the chemical nature of the nutritional defi- 

 ciencies of arachin: D. Breese Jones, and Henry 

 C. Waterman. Estimations of the digestibility 

 in vitro of variously treated preparations of arachin 

 (the principal protein of the peanut, Arachis hypo- 

 gcea) by the method of Waterman and Johns indi- 

 cate: (1) that this protein is incompletely diges- 

 tible, and that this condition is not altered by 

 boiling with water at ordinary pressure or by cook- 

 ing under a steam pressure of 15 lbs.; and (2) 

 that the nutritional failure of arachin is due to the 

 retention of a considerable part of one or more of 

 the essential amino acids, the most conspicuous of 

 which is histidine, in the indigestible complex. The 

 total amino acid composition of arachin would 

 almost certainly be quite adequate, if it were avail- 

 able. The experiments indicate that the incomplete 

 digestibility of arachin is not due to changes 

 brought about by the treatment involved in its iso- 

 lation, but is a native property of the protein. The 

 high nutritional efficiency of peanut meal is there- 

 fore to be attributed to the presence in the meal of 

 sources of amino acids which supply essentials con- 

 tained in an unavailable form in arachin. 



A chemical study of the proteins of the adsuhi 

 bean, Pliaseolus angularis: D. B. Jones, A. J. 

 Finks, and C. E. F. Gersdorfp. Two globulins 

 and a small amount of albumin have been isolated 

 from the total proteins of the Japanese adsuki 

 bean, Pliaseolus angularis. The a globulin, ob- 

 tained in 0.35 per cent, yield, was precipitated 

 from a 5 per cent, sodium chloride extract of the 

 bean meal by making the extract 0.3 saturated with 

 ammonium sulfate, dissolving the resulting precipi- 

 tate in distilled water and dialyzing the solution 

 in running, chilled water for 9 to 12 days. This 

 globulin coagulated at about 88° C. Elementary 

 analyses of several preparations showed them to 



