YELLOW FEVER. 437 



if I had been fully prepared for the work, could 

 not have found the time to obtain pure cultures 

 of each micro-organism encountered, and to make 

 inoculation experiments for the purpose of deter- 

 mining whether any one of them had specific 

 pathogenic properties. Pasteur was engaged for 

 several years in his study of pebrine, the parasitic 

 disease of silkworms upon which he may be said 

 to have founded his scientific reputation. That the 

 etiology of yellow fever was not worked out during 

 the three months' stay of the Havana Commission 

 in Cuba cannot therefore appear surprising to 

 those who know the difficulties of such an under- 

 taking ; and if Dr. Carmona, or Dr. Somebody-else 

 succeeds in carrying off the laurels due to a dis- 

 coverer, it will be rather a matter of luck than of 

 science, unless he attacks the problem by the 

 painstaking and tirnetaking methods which have 

 been perfected by Pasteur, Koch, and other pio- 

 neers in this line of investigation. Dr. Carmona 

 says : 



" If a portion of urine be allowed to evaporate spon- 

 taneously, and the residue be examined microscopically, 

 the protoplasmic substance containing abundant spheri- 

 cal yellow granulations, mycelial tubes, and crystals of 

 cholesterine and tyrosine, before mentioned, are seen. 

 The free extremities of many of the mycelial threads 

 were gradually dilated, somewhat resembling the ex- 

 tremity of the olfactory bulb." These dilated extrem- 

 ities Carmona calls oogonos, and they measure from 

 10 to 60 fi. 



Yellow fever urine is an acid albuminous fluid, 



