N. MATERIA MEDICA, THERAPEUTICS, AND HYGIENE. 617 



quently in the iinvaccinated. 4. In the Children's Hospital, 

 where the mortality has been so enormous, and has specially 

 prevailed in the hemorrhagic form, its fatal course has chiefly 

 been among the unvaccinated. These facts will, at a later 

 period, be demonstrated by the publication of the full statis- 

 tical data, and it is hoped they will teach the opponents of 

 vaccination a much-needed lesson. 20 A, JVbv. 30, 1872, G17. 



ACTIVE PRINCIPLE OF VACCINE VIRUS. 



The vaccine matter, or virus, contains, in an albuminous 

 fluid, diff*erent formations, among which very small micro- 

 scopic grains are conspicuous. Messrs. Chauveau and Keber 

 consider these as the very carriers of the vaccine matter. 

 Mr. Ferdinand Cohn was off*ered an opportunity to examine 

 the subject more closely, and makes the following report : 



At first he raises the question. Are these grains, jDerceived 

 by all observers, constituent parts of the virus, or accidental 

 admixtures? Experiments instituted with all possible pre- 

 cautions led to the conclusion that they exist in the freshest 

 virus, and have to be considered as constituents. These 

 globular corpuscles fill the vaccine matter quite equally. 

 They are without spontaneous motion, but show molecular 

 motion. Their size could not be ascertained accurately, be- 

 ing beyond our present means of microscopical measurement, 

 but is certainly less than 0.001 of a millimeter perhaps one 

 half or three quarters of it. At first they are mostly single, 

 rarely in pairs, but increase rapidly in number when the ob- 

 servation is continued for some time with proper precautions. 

 They form entire rows, and, after some hours, irregularly 

 connected groups. This extremely rapid and uninterrupted 

 augmentation proceeds from cross-division of the cells. From 

 these observations Mr. Cohn considers the corpuscles of the 

 virus as living, independent organisms, belonging to the 

 class of schizomycetie, which, as the smallest and simplest 

 of all organisms, multiply only by the division of cells. 



In conclusion, Mr. Cohn discusses the question whether 

 these corpuscles are in fact the carriers of the contagion, and 

 comes to the conclusion that this is highly probable, yet not 

 definitely decided. He inclines, however, to a modification 

 of this statement, viz., he would consider them rather as 

 originators than carriers, in so far as.he believes them to act 



