364 DOURINE 
Schneider and Buffard, Nocard and others found the trypanosoma 
in the blood and exudates of horses, asses and dogs suffering from 
dourine but failed to find them in the same localities in animals of the 
same species which were free from dourine. The infected blood pre- 
served for 24 hours in sealed glass tubes, and then inoculated into 
dogs produced characteristic symptoms and lesions with many 
trypanosomes in the blood. Inoculation into two other dogs, with 
the same material, but at the end of 48 hours, produced a slight 
transient hyperemia only, without local lesions or propagation of the 
parasite in the blood. The blood from the same animal inoculated 
after fifteen days gave negative results. 
Baldrey found Romanowsky’s and Wright’s modifications of Leish- 
man’s method the best methods for staining the trypanosoma; the 
latter is very useful and handy, as no mixing of solutions is necessary 
and no fixing required. 
Romanowsky’s Stains: 
STOCK SOLUTION NO. 1 
Hochst’s medicinal methylene blue ..............0.-2 0000s e eee pistons 1 part 
Sodium carbonate pure... osc uccnee de peed ae eee eee es eee 0.5 parts 
Distilled WAGER oj ecccc eioece se sie vieranannjaie geamdee seanmase Rd SO SOEs Mee 100 parts 
Place this solution in an incubator at 37° C. for two or three days, when a purple color 
will be noticed at the edges of the liquid; this depends upon the formation of a new red 
color—methylene red—which combined with eosin forms the active principle of the 
stain and has a particular affinity for chromatin. Unless this polychromatophylic 
change takes place the solution is useless. 
STOCK SOLUTION NO. 2 
SOBA seas cvtcenesaewaia we oe er elisa nomics OO uN Sao dateenRnaNIS 1 part 
AW EET ce sceck cba stcw Sesto i sen Dect en ce td lol ath ac tds tee 1000 parts 
For staining, the stock solutions are separately diluted with water, 5 parts of stock 
solution to 100 parts of water. 
In order to obtain a smear, prick the center of the plaque and take a drop of blood 
on a slide, which should be chemically clean, having been taken from an alcohol bottle 
and dried with a clean piece of art muslin. Then, either in the ordinary way with a 
piece of cigarette paper, make a thin even smear over the slide, or, as an easier and 
equally efficient method, take a perfectly clean flat large-sized needle and place it 
edgeways on the drop, when the capillary attraction of the needle will cause the blood 
to stream right across the slide; then evenly and gently draw the needle down the 
length of the slide, and a very even smear may be obtained. Quickly dry the smear in 
the air by waving rapidly about. which prevents the red corpuscles from crenating; the 
slide can then be kept indefinitely or used at once. The advantages of using a slide 
instead of a cover-glass are that you get a much larger field on which to work, it is 
much more easily manipulated and it can be kept without any mounting. Place the 
film in absolute alcohol or alcohol and ether, for fifteen minutes to half an hour to fix. 
