1923] Wagciicr: Leishmdnia tropica and Leishmunia infanfum 47!! 



powder was obtained from each species and from the control, liilikc 

 the typhoidin, however, these dry powders would not go into solution 

 in saline, and no reaction occurred in the rabbits from the intra- 

 dermal injection of 0.2 c.c. of the suspension of 1 part of powder in 

 100 parts of saline. It was therefore decided to grind each of the 

 powders in a mortar, while adding slowly a weakly alkaline solution 

 such as that recommended by Coca (1922) for the extraction of 

 proteins from pollens and danders. So 100 parts of the extracting 

 fluid of Coca, consisting of sodium chloride 0.5 per cent, sodium 

 bicarbonate 0.05 per cent, and carbolic acid 0.4 per cent, in sterile 

 distilled water were added to one part of dry powder. The suspen- 

 sions were then placed in sterile containers, covered with toluol, and 

 allowed to stand at room temperature for three days. Unfortunately, 

 there was not a sufficient quantity of the extracted proteins to enable 

 us to follow Coca's technique farther and determine the nitrogen 

 content of the extract before using it. These alcoholic extracts will 

 be designated alcoholic extracts of L. tropica, and L. infa.ntwm. 



At the same time a number of cultures of each species of Leish- 

 mania were washed off in saline, the washings eentrifuged, and the 

 protozoans in the bottom of the tube diluted with Coca's extracting 

 fluid until 1 c.c. contained 2,000,000 organisms. These suspensions, 

 spoken of hereafter as alkaline extracts of L. tropica and L. infantum, 

 were also covered with toluol and allowed to stand at room tem- 

 perature for three days. The alcoholic and alkaline extracts were 

 then eentrifuged at high speed for half an hour, and the super- 

 natant fluid decanted into sterile tubes. 



One normal and four immune rabbits which had been shaved on 

 the back were inoculated intradermally with 0.2 c.c. of each extract 

 and with a control of the extracting fluid to which a little toluol had 

 been added. All extracts were tested for their sterility before being 

 used for the inoculations. 



The extracts prepared from the protein precipitated by means 

 of alcohol gave unsatisfactory results. A reddened and occasionally 

 a slightly indurated papule, indistinguishable from the control of 

 that series, appeared within 24 hours and then disappeared after 48 

 hours. The alkaline extracts of L. tropica and L. infantum, on the 

 other hand, produced at the end of 24 hours a small reddened papule 

 which reached its height in 48 hours and persisted for five days. The 

 center of this papule in all the immune animals consisted of an 

 irregular ivory-white area 1 to 2 mm. in diameter, surrounded by an 



