V 



ABSTRACTS 



Authors of scientific papers are requested to see that abstracts, preferably 

 prepared and signed by themselves, are forwarded promptly to the editors. 

 The abstracts should conform in length and general style to those appearing in 

 this issue. 



ANALYTICAL CHUMISTRY .—Application of the interferometer to 

 gas analysis. Junius D. Edwards. Bur. Standards Techn. 

 Paper 13L Pp. 19. 1919. 



One of the most useful of the physical methods applicable to gas 

 analysis is that of gas interfe^omet^^^ By the application of a new 

 method of calibration, previously described in Scientific Paper 316, 

 the use of the gas interferometer has been simplified and extended. 

 The relation between the refractivities of the gases and the indications 

 of the interferometer is discussed for various typical cases and illus- 

 trative calculations given. The determination of helium in a mixture 

 of gases is one case of interest which is discussed. It is of importance 

 because of the scarcity of analytical methods for determining helium. 

 Other cases discussed are the eff'ects of variations in the composition of 

 air where it is a component of mixtures under test, the analysis of flue 

 gases, the relative sensitivity of the interferometer for different gases 

 and points about the operation of the interferometer. J. D. E. 



BIOCHEMISTRY. — Biochemical studies of the saliva in pellagra. 

 M. X. Sullivan and K. K. Jones. PubHc Health Reports 24; 

 1068. No. 20, May 16, 1919. 



In pellagra the condition of the mouth, and especially of the tongue, 

 is of considerable importance in establishing a correct diagnosis. The 

 true pellagrous tongue is vividly red and more or less swollen. The 

 literature also speaks of salivation as a symptom of pellagra. In care- 

 ful quantitative studies at the pellagra hospital, Spartanburg, South 

 Carolina, it was found that, though there were cases of increased sali- 

 vary flow, the salivation spoken of by the patients was often apparent 

 rather than real and was seemingly due to some inhibition of swallowing 

 combined with a peculiar ropy change in the saliva or high content of 

 mucus which made the presence of saliva in the mouth more obvious. 

 Occasionally also the flow was very slow, but in general it was within 

 normal limits, which vary considerably. The specific gravity of the 



415 



