Botulinus Toxin. 



299 



expect that the smaller particles of such a dissociated toxin might 

 dialyze easier than the coarser aggregates of the crude toxin. 

 The experimental evidence indicates the reverse to be the fact. 

 While the crude toxin dialyzes with a comparative ease, the 

 acidified toxin remains quantitatively inside the parchment 

 thimble. 



May not this phenomenon be explained on the basis of the 

 theories offered by some physical chemists 3 namely, that while the 

 coarser aggregates of protein carry no charge, the increase in the 

 dispersion resulting upon dilution and especially upon acidification 

 confers the electrical charge on such dissociated particles. In 

 virtue of this charge these smaller particles are adsorbed to the 

 membrane whereas the coarser particles of undissociated substance 

 were able to go through the pores of the membrane. 



135 (1882) 



The diagnosis of kala-azar by blood culture. 



By CHARLES W. YOUNG and HELEN M. VAN SANT (by invitation) 



[From the Department of Medicine, Peking Union Medical College, 



Peking, China.] 



The usual method for diagnosis of kala-azar by means of 

 cultures has been from spleen juice obtained by puncture and 

 aspiration with a syringe and needle. Prolonged bleeding-time 

 is fairly constant in advanced kala-azar. The risk of bleeding 

 from the needle wound in the spleen together with the possibility 

 of tearing that organ by a sudden movement of the patient during 

 puncture, makes a safer method for cultural diagnosis desirable. 



Meyer and Werner 1 reported in 1914, five successful cultures 

 from a single specimen of blood. Row 2 and Korke 3 each report 

 one. Cornwall and LaFrenais 4 succeeded in seven cases; however, 



'Robertson, T., Brailsford. The Physiological Chemistry of the Proteins, 1918, 

 P- 153. 



1 Meyer, M., and Werner, Deutsch. Med. Wchnschr., 1914, xl, 67. 



2 Row, R., Indian Jour. Med. Res., 1914, July (quoted in (4)). 



3 Korke, V., idem. 



4 Cornwall, J. W., and LaFrenais, H. M., Indian Jour. Med. Res., 1915-16, iii, 



698. 



