The Determination of Hemoglobin. 175 



ence or absence of the fat-soluble vitamine has not yet been 

 ascertained. The mineral constituents of the soy bean are in- 

 adequate for growth. Whether the deficiency is a qualitative or 

 quantitative one remains to be determined. Rats eat foods con- 

 taining commercial soy bean flour more readily than those con- 

 taining meal made by grinding the entire seed. The latter is 

 non-toxic; for the few animals which have eaten enough have 

 grown well. Preliminary experiments indicate that the heating 

 to which the commercial soy bean flour is subjected may be the 

 cause of the superiority of the latter. Unlike cotton seed, soy 

 beans extracted with ether are not improved in nutritive value. 

 Unheated soy bean meal and corn gluten has proved satisfactory 

 as the sole source of protein in the diets of chickens. We are 

 continuing our investigation of the nutritive value of this seed. 



104 (1282) 



The determination of hemoglobin. 



By Walter W. Palmer (by invitation). 



[From the Hospital of the Rockefeller Institute for Medical Research, 



N. Y.] 



The method for the determination of hemoglobin described 

 below has proved accurate and convenient. 0.1 c.c. of blood is 

 introduced into a 10 c.c. volumetric flask half filled with 0.4 per 

 cent, ammonia water (4 c.c. strong ammonia in 1 liter of water) 

 and filled to the mark with the ammonia solution. The contents 

 are poured into a large test tube (25X200 mm.) and illuminating 

 gas bubbled at a rapid rate through the hemoglobin solution for 

 at least 30 seconds. The resulting carbon monoxide hemoglobin 

 is then compared with a standard solution in a colorimeter 

 (Duboscq). 



The standard is a I per cent, solution of defibrinated ox or 

 human blood having an oxygen capacity of 18.5 per cent, which 

 has been thoroughly saturated with carbon monoxide. The 

 oxygen capacity may conveniently be determinated by the method 

 described by Van Slyke in the Proceedings of this Society, 191 7, 

 XIV, 84. It has been found convenient to prepare a 10 or 20 



