TRYPANOSOMES, TRYPANOSOMIASIS, AND SLEEPING SICKNESS 23 
when the blood was inoculated that rats which received 0-5 to o - 8 c.c. of pure blood 
died in twenty to twenty-eight hours, while controls injected with a weaker solution, 
o*l to 0-5 c.c, survived. On three consecutive days batches of four rats were 
inoculated intraperitoneally ; the two animals which received the higher amounts 
were killed, the other two survived. A repetition of these experiments gave the 
same results. Cultures made from the rats remained negative, and films from the 
inoculation mixture, peritoneal cavity and heart blood of the rats, showed no bacteria. 
This rabbit died a week later. Maceration of its organs and treatment in the usual 
manner tailed to reveal a toxine. The organs ot animals dying or killed when 
numerous trypanosomes were present in the blood and in the juices of the 
organs, or at any time when the parasites have almost disappeared, have been 
used. The precipitates obtained from them have neither produced any effect nor 
afforded any protection against infection. The organs of the two cases ot sleeping 
sickness were tried with like negative results. Peritoneal and pericardial exudates 
and fluid from oedematous tissues containing parasites have been ground up and 
injected also with negative results. It is possible, if they could be procured in large 
quantities, that some substances might be obtained which would cause a reaction, but 
the quantity of fluid ordinarily obtainable is limited. Centrifugalization of large 
quantities of blood renders it possible to collect enormous numbers of trypanosomes, 
but they are mixed with leucocytes. Efforts to get rid of these latter have not 
been successful. Inoculation of these parasites after they are killed by heat or cold 
or kept for a sufficient time have failed to produce any effect. From the products of 
culture tubes no toxine has been found, and animals inoculated with such contents 
have shown no evidences of intoxication. 
Agglutination 
The possibility of the agglutination of the parasite acting as an adjunct to the 
diagnosis of the disease has been realised. The results are not satisfactory. Blood, 
from an animal showing parasites, when defibrinated and mixed with serum from a 
native or animal suffering from the disease has been used. The parasites do not 
agglutinate. Serum from an animal continually injected with living trypanosomes 
shows the same negative results. In both cases there is a certain agglomeration of 
the parasites, but this is also usually obtained if norma] serum be used. The serum 
from a native or animal added to deribrinated blood from the same case shows a slight 
agglutination. The exudate from a bleb causes no definite agglutination. If the 
trypanosomes be rendered immobile by the addition of weak formol before the serum 
is added, a partial clumping of the parasites may occur. Brumpt and Wurtz added 
potassium citrate solution to blood containing parasites to prevent coagulation, and 
then added serum from a sleeping sickness case. A rapid agglutination of the 
trypanosomes occurred. As they point out citrated blood containing parasites shows 
agglutination of the trypanosomes in a short while. In our opinion blood, to which 
