224 BLOOD. 



Popp, with that of Scherer. Hinterberger found that the amount 

 of albumen, when determined according to Becquerel and Rodier (by 

 extraction of the solid residue of the serum with various indifferent 

 solvents), was always somewhat larger than when determined by 

 Scherer's method ; this is, however, not merely the case with the 

 serum, but also, in a still higher degree, with the cruor when free 

 from fibrin (the blood-corpuscles + the enclosed serum) ; that is 

 to say, here also the substance obtained by coagulation through 

 the aid of acids, amounts to less than the residue which we 

 obtain after treating the solid constituents of the cruor with ether, 

 alcohol, and water. This result, which can be observed in any 

 analysis of the blood, partly depends upon the circumstance that 

 when the coagulation is effected by the aid of acids, they extract 

 from the coagulable matter a small quantity of earths which would 

 naturally remain in the substance, if treated only with indifferent 

 menstrua ; but partly also on this, that, by the treatment with such 

 menstrua certain alkaline salts, and probably also organic matters, 

 are extracted from the residue, which, in the coagulation, retain in 

 solution a certain quantity of albuminous substances from the 

 fluid, so that this portion is abstracted from the coagulation. 



A. Becquerel* has recently availed himself of Biotas discovery 

 of the rotatory power which dissolved albumen exerts on polarized 

 light, in order to determine the quantity of albumen dissolved in 

 the serum, as Bouchardat had previously attempted to do. We 

 cannot give a minute description of the instrument in this place, 

 but we may observe that it enables us to measure the rotation 

 which a pencil of light undergoes to the left hand in consequence 

 of the albumen contained in the fluid. According to Biotas 

 formula, the rotatory power of albumen is 27 36'; in BecquerePs 

 apparatus, the albuminimeter, each minute of deviation which the 

 pencil of light undergoes, corresponds to 0*18 of a gramme of 

 albumen in the solution inclosed in the apparatus, and hence every 

 degree corresponds to 10'8 grammes. Becquerel has found, by 

 repeated observations, that there is a perfect coincidence between 

 this physical and the chemical analysis; but this is a subject 

 requiring further investigation ; in the first place, because, accord- 

 ing to Becquerel's admission, even the chemical mode of deter- 

 mining the albumen does not give strictly accurate results ; and 

 secondly, because the serum always contains traces of sugar, which 

 may, to a certain degree, modify the amount of the deviation. 



The determination of the salts of the serum and of the cruor 

 * Compt. rend. T. 29, p. 625. 



