284 GLANDERS AND FARCY. 



course, I cannot answer. When Gerlacli first pronounced pleuro-pneu- 

 monia of cattle a pure contagion, that is, a disease propagated exclu- 

 sively bj^ means of infection, Professor Spinola asked pertly if Gerlacli 

 liad imported pleuropneumonia from the moon, but failed utterly — and 

 everybody else, too — to show a solitary case of an unmistakable and well- 

 authenticated spontaneous development. If any one can show me a 

 case of spontaneous glanders, not caused by infection, or give satisfac- 

 tory and unmistakable proof that a protopathic or deuteropathic develop- 

 ment of glanders has occurred, I will take back what I have said, but 

 not before. 



The contagion. — The contagion must be considered as the exclusive 

 cause of glanders. When I lived in Dixon, Lee county, Illinois, from 

 the fall of 18G5 to September, 18G8, 1 had an opportunity of observing 

 numerous cases of glanders. A fi-iend of mine, 1). W. McKinney, dealer 

 in horses and proprietor of a livery-stable, knew nearly every horse in the 

 whole county, and taking special interest in those cases of glanders, 

 assisted me in inquiring into the history of every horse alfected. As a 

 result, every case, without exception, was traced back to an infection by 

 condemned United States army horses that had been sold to the farmers. 



The contagious principle is developed during the very first stages of 

 the disease, and even before plain symptoms have made their appear- 

 ance. It exists most concentrated in the immediate products of the 

 morbid process, but especially in the discharges from the nose, and in 

 the contents of the glanders and farcy ulcers. It is present also in aU the 

 secretions and excretions of the affected animals, as has been proved by 

 numerous direct experiments. Professor Gerlacli, in order to ascertain 

 if the contagion, is contained not only in the fluid animal humors and 

 excretions, and in the fluid and solid iiroducts of the morbid process, 

 but also in the pulmonal exhalation and in the perspiration, has made 

 several interesting exj)eriments, and has found that an inoculation of 

 a healthy horse with artificially condensed exhalation and perspiration 

 of a glandered animal produces the disease. He has, however, not suc- 

 ceeded in communicating glanders by injecting defibrinated blood of 

 glandered horses (100 and 200 grains respectively) into the veins of 

 healthy animals. Still, the contagiousness of the blood has been estab- 

 lished long ago by Abildgardt and Viborg in Copenhagen. 



The experiments of Gerlacli and of others, and numerous c?dnical 

 observations, too, have proved beyond a doubt that the contagion con- 

 tained in the exhalation and iierspiration clings, though only in small 

 quantities, to the aqueous vapors exhaled by the respiratory organs and 

 perspired by the skin. The contagious principle, therefore, is volatile 

 only in a limited degree, and to produce an infection by means of the 

 exhalation and perspiration at a distance of several feet requires usually 

 some length of time. So it happens very often that a horse occupying 

 with a glandered horse the same stable, but not the same stall, remains ex- 

 empted. The more forcible and accelerated the breathing, and the more 

 abundant the perspiration of the horse afiected with glanders, the 

 greater, it seems, is the danger of an infection of healthy horses that 

 are near, or occupy the same stable. 



Another question not easily answered, and yet an object for investi- 

 gation, may be asked ; that is. Do organic forms constitute the conta- 

 gion 5 is the contagious principle bound on, or inseparable from, organic 

 forms ; or is its action merely a chemical one f On this question the 

 opinions of the best authorities differ. Professor Gerlach, in his suc- 

 cessful experiments with condensed exhalation and perspiration, found 

 no organic forms whatever in the perfectly limpid drops ; further, he 



