VETERINARY SCIENCE AND PRACTICE. 027 



culture, they should have been alive, unless some substance esix'cially iiiimical to 

 their growth was i>ro(lueetl in the cultures. 



"These ex])erinients show clearly that the tuberculosis bacillus can be readily 

 accustomed to an acid nutrient fluid, that it can ousily adapt itself to tiic changed 

 conditions of life, and that even a small amount of free hydrochloric acid does not 

 interfere with its growth. They tend to show further, we think, that under certain 

 conditions there is i)robably a jyoisonous sul)stance produced by the germs which is 

 inimical to their own life." 



Serum diagnosis of hog cholera, C. F. Dawson {Separate from 

 X. Y. Mc<l. Jour. ls!)7j Fi'b.:>0, pp. .V). — The author has made an applica- 

 tion to hog cholera of a method discovered by Widal for diagnosing with 

 ease and certaiut}- the existence of ty])hoid fever. In Widal's method, 

 a bouillon culture of typhoid bacillus is subjected to microscopical 

 examination to determine the isolation and motility of the individual 

 bacteria. A drop of blood from the i)atient and a few drops of the cul- 

 ture are then mixed together on a watch glass and a hanging-drop 

 culture made. It is found that the bacilli lose their motility and become 

 aggregated into masses which are separated by wide spaces. The lat- 

 ter are dotted with less motile bacteria, which may be seen to approach 

 the masses and finally become adherent to them. Such phenomena are 

 not found in preparations made from the blood of healthy persons nor 

 from those suffering from such diseases as nephritis, tuberculosis, 

 l)neumonia, icterus, and rheumatism. 



In the author's experiments, which are preliminary to more extended 

 investigations, a rabbit was inoculated with hog cholera by a subcuta- 

 neous injection of a bouillon culture. Five days later a little blood 

 from the ear of the rabbit was smeared on a clean cover glass and 

 allowed to dry. Then a drop of bouillon culture of hog cholera bacil- 

 lus was placed upon the dried blood and the cover glass inverted over 

 a hollow ground slide and examined microscopically. By the time the 

 bacilli had been brought into focus they were found to have become 

 motionless and aggregated into clumps exactly as described by Widal 

 in reference to the typhoid bacillus. A control experiment made with 

 the blood from a normal rabbit exhibited no such i^henomena. Experi- 

 ments made to learn the effect of hog cholera Idood serum upon typhoid 

 fever bacillus and the liavillu.s coll communis gave negative results. 

 The method is believed to be of considerable value, as it will enable the 

 detection of hog cholera before the ordinary symptoms are apparent. 



Report of the commissioners on diseases of domestic ani- 

 mals, 1896 [Kpt. [CoHnccticut\ Comm. JJiseancs JJomr.stic Auimah, 

 189G, pp. 23). — The report deals entirely with tuberculosis, and states 

 that out of 0,304: cases examined, 14.L* ]»er cent, or 897, were condemned. 

 Six hundred and fourteen herds were tested, of which ."•DT contained no 

 evidence of disease. Post-mortem examinations of the others revealed 

 140 very bad cases, G40 well marked, S.l light, and 19 cases in which 

 no lesions Mere discoverable by the naked eye. The report goes on to 

 state that the method of testing by injection of tuberculin is growing 



