122 



THE AMEIllCAN MONTHLY 



[July, 



dead birds beneath the skin. The 

 disorder is not accompanied by erup- 

 tions on the skin, but is characterized 

 by elevated temperature, dullness and 

 loss of appetite, often deep somno- 

 lence, by paleness of the fleshy parts 

 about the head, and by yellow colora- 

 tion of that part of the excrement 

 which is separated by the kidneys. 

 The most marked and constant lesion 

 is an intense congestion of the liver 

 with enlargement and softening; and 

 there are frequently other complica- 

 tions which, for the purposes of this 

 communication, it will be unneces- 

 sary for me to enumerate. My aim 

 is simply to establish the fact that this 



Fig. 34. 



Fig. 34. — Micrococci of fowl cholera, from a btained 

 preparation of cultivated virus, X 1000. 



is a virulent internal disease, or in 

 other words a contagious fever. 



A little over two years ago M. 

 Pasteur presented his communica- 

 tion on this affection to the Acade- 

 my of Medicine,* and shortly after- 

 wards the writer began his investiga- 

 tions of it which were continued until 

 the present, and are not yet entirely 

 finished. The facts demonstrated by 

 these researches, which bear upon the 



* L. Pasteur. Sur les maladies virulentes 

 et en particulier sur la maladie appelee vul- 

 gairement cholera des poules. — Bulletin de 

 I' Academic de Medeciiic, iSSo, p. 121. 



etiology of the disease, are briefly 

 as follows : — 



I . The virulent liquids of the foivVs 

 body coutain micrococci. — If we exam- 

 ine the blood or tissue-juices of a bird 

 nearly dead of cholera, or from one 

 that has recently died, we may find a 

 considerable number of granules hav- 

 ing the dumb-bell form, or some ap- 

 parently single globules, caused by 

 one part being directly beyond the 

 other in the line of vision. These 

 bodies are extremely small, less than 

 3o-o"Tn)- th of an inch in short diameter, 

 and perfectly motionless. If the mi- 

 croscopist relies upon this examina- 

 tion alone, however, it would not be 

 strange if he remained in doubt as to 

 the nature of the granules which he 

 has discovered. They might very • 

 reasonably be considered as granular 

 fibrin, as the debris of broken down 

 cells, or as particles of uncertain na- 

 ture which have gained entrance from 

 the atmosphere. It will be found 

 difficult in many cases, if not gener- 

 ally, to obtain the bacterial reaction 

 to coloring matter by staining with 

 anilin, violet, or other agents. 



Fortunately, the microscopist of to- 

 day has the means of accurately de- 

 termining the nature of such granules 

 — this is accomplished by their culti- 

 vation in suitable media. Pasteur 

 demonstrated that these granules 

 might be cultivated in a liquid ob- 

 tained by simmering the muscles of 

 fowls in v/ater and afterwards filtering 

 to transparency and sterilizingby heat; 

 this I have confirmed by long-con- 

 tinued and careful experiments. 



Can we be certain, however, that 

 the organisms which we are cultivat- 

 ing, really existed in the blood of tlie 

 fowl while circulating in the veins, or 

 may they not have gained entrance 

 from the air ? This objection is more 

 pertinent than many imagine, for not- 

 withstanding assertions, the proba- 

 bilities are that very few persons, 

 taking the world over, have made 

 pure cultivations from virulent 

 liquids. Klein believes that he has 

 done this v.'ith the virus of the dis- 



