CONTAGIOUS DISEASES OF DOMESTICATED ANIMALS. 255 



origin or permauent source in the South, I could not help arriving at 

 the conclusion, after taking all the peculiarities presented into consid- 

 eration, that the pathogenic principle ^bacterium) must be connected 

 with, or be dependent upon, the flora of the Southern States, and 

 cannot be the direct product of the climate or the higher average 

 temperature. Having f»)und the bacilli in the morbidly atfected tissues 

 several years ago at my tirst examination of the southern cattle fever at 

 Champaign, and considering them, even at that time, as the probable, 

 or at least possible, cause of disease, I naturally looked, when in Texas, 

 for something corresponding to be found on, or to be connected with, 

 the herbage and grasses which constitute the food of the cattle on the 

 Texas cattle ranches. The well known experiments of Dr. Buchner 

 directed my attention to infusions — natural and artificial — of the dead 

 and decaying grasses of Texas hog-wallow land — to those of the latter 

 in particular, as it was repeatedly stated by experienced Texas ranch- 

 men that hog-wallow land is considered as the most dangerous grazing 

 ground for cattle recently imported from the North. The natural in- 

 fusions 1 found in the si)ring prepared in the so-called hog-wallows 

 themselves, alid the artificial infusions were made by putting some of 

 the dead grass in a vessel and pouring rain-water over it. When ex- 

 amining my infusions, I found, as could scarcely otherwise be expected, 

 a variety of microscopic organisms (bacteria), but among them, in larger 

 or smaller numbers, invarially a bacillus which, in every respect, closely 

 resembled both in size and form those bacilli which I had found before 

 and found afterwards in the liv^er and spleen of the diseased cattle — 

 certainly something worthy of further investigation. 



As I look upon it, the principal object in investigating an infec- 

 tious disease, ])arti(;ularly if the same is very fatal, causes great 

 losses, and is capable of spreading a great distance, must be to ascer- 

 tain the true cause, and to become acquainted with its nature and its 

 mode of action, and the means and conditions necessary to its exis 

 tence, propagation, and communication. As long as we are in tlie 

 dark in regard to the cause of a disease, particularly if the latter is 

 infections, our treatment and our i^rophylactic measures can only be of 

 an empirical charactei-, and at best be very uncertain. But as soon as 

 we know the cause, its mode of action, its means of existence, and its 

 manner of pro[)agation and communication, we have gained a great 

 advantage, for then, if tlie cause is accessible and can at all be de- 

 stroyed its effects can be neutralized or its propagation and communi- 

 cation can be prevented. The possibility is then given to devise 

 rational measures which will have the desired eftect. Therefore, sin- 

 cerely believing, nay. almost convinced, that my endeavors to discover 

 the cause of the southein cattle fever are in the right direction, it is 

 and has been my desire to subject my conclusions, above stated, to a 

 practical test, and to decide by experiment whether the same are cor- 

 rect or erroneous. Last year 1 made some etibrts in that direction, but 



