THE AMERICAN 



MONTHLY 



MICROSCOPICAL JOURNAL 



Vol. VI. 



Washington, D. C, Febrcjary, 1885. 



No. 2. 



The Microbe of Yellow Fever— | 

 Preventive Iiioculatioii. j 



1!V M. M. T). FREIRE VXD REBOLR- 



GEON.* i 



In 1880 Dr. Domingo Freire, pro- 

 fessor of biology in the medical faculty ; 

 at Rio Janeiro, in a memoir which 

 appeared based on his scientific work, j 

 had already published the result of ] 

 his first discoveries regarding the 

 microbe of yellow fever and regard- 

 ing the employment of salicylate of. 

 soda as a curative means. Since that 

 time M. Freire has not ceased to study 

 the question, regarding it indeed 

 from the true point of view, namely, 

 the microbial nature of this fever, the 

 possible culture of the microbe, its 

 physiological and chemical transfor- 

 mations, and finally its attenuation. 

 To-day, after a rigorous experimenta- 

 tion. M. Freire gives the proofs of 

 the contagion, and demonstrates the 

 existence of ptomahie in the cases of 

 yellow fever, of which he indicates 

 the cliaracter. The culture of the 

 micro-organism and the artificial re- 

 production of the blackish matter of 

 the somiting, the infecto-contagious 

 nature of the malady, and finally the 

 inoculation-preventive by aid of a 

 liquid attenuated by culture, have been 

 the object of his researches. 



When the blood of a subject recently 

 deceased from yellow fever is exam- 

 ined, or, better still, the blood of 

 an inoculated animal at the point 

 of death by the same disease, there 

 may be seen in the field of the micro- 

 scope : I . A considerable quantity of 

 extremely small micracocci, hyaline 



* A paper presented to the French Academy by M. 

 Bouley. Translated by A. N. Skinner from Loniptes 

 Rendus , November loth^ 1884. 



in appearance. 3. Cellular bodies- 

 attaining only one-fourth the volume 

 of a blood-corpuscle. 3. The same 

 cellular bodies larger and more 

 opaque. 4. Large cellules afiecting 

 the form of an epithelial cellule of a 

 blackish aspect, showing their torn 

 enveloping coats and permitting to 

 escape a quantity of the above de- 

 scribed micrococci. 



On the other hand, if in a bouillon 

 devoted to culture "by surrounding it 

 with the required precautions, we 

 seek to cultivate the micrococcus 

 found in the blood, at the tempera- 

 ture of 38' to 39°. we see in a few 

 hours its successive transformations 

 and passage through all the states 

 which have been just indicated. If 

 we leave the liquid in repose the in- 

 ferior part becomes entirely blackish ; 

 microscopic observation demonstrates 

 that this deposit is only formed of the 

 cellular envelopes of the micro-organ- 

 ism which has reached the last period 

 of its action. Chemical analysis de- 

 monstrates besides that this cellular 

 envelope is transformed into pto- 

 maine. It is then easy to deduce 

 from this series of observations that 

 the yellow fever is determined by the 

 presence in the blood of a cryptococ- 

 cus which follows rapidly all its phases 

 of evolution, and that the blackish 

 matter of the vomiting, or of the de- 

 jections of sick persons, is formed 

 only of the debris of this same cryp- 

 tococcus which has become poison by 

 its transformation into ptomahie., and 

 not by the removal of the blood cor- 

 puscles through hemorrhage as has 

 been believed for a long time. 



Encouraged by his successive dis- 

 coveries, and proceeding always with 



