5 °-’ 
Treat went of I. rhodesiensc in rats by subcutaneous injection 
of vaccines. 
II. VACCINE TREATMENT 
In view of the extensive development of vaccine treatment in 
disease, we have carried out some experiments in the treatment ot 
trypanosomiasis. These experiments are few, and therefore 
inconclusive, but they have produced results of interest, and we 
are continuing the experiments in the hope of gaining further 
knowledge. 
The vaccine used by us was not a true vaccine, because it 
contained serum, blood corpuscles, leucocytes, and the bodies ot 
dead trypanosomes. It will thus be noted that vve injected a rather 
complicated fluid, and that it was only a vaccine in the sense that 
it contained the bodies of dead trypanosomes. 
I he vaccine was prepared by searing the surface of the heart 
with a hot needle in order to get a sterile portion, and through this 
me mood was drawn into a sterile pipette and mixed with normal 
saline. 1 his mixture was placed for half an hour in an incubator 
a * 55 C.. and finally a little trikrcsol was added. A count was 
made of the parasites in i c.mm. before they were subjected toheat. 
and appropriate dilution was carried out with normal sterile salt 
solutions. 
There are two distinct points at which we may prepare this 
so-called vaccine. We may prepare it at the height of the rise of 
the trypanosomes in the peripheral blood, or it may be prepared 
when the trypanosomes are few in number. 
In the former case vve have a condition in which the numbers 
trypanosomes are great, and probably the anti-bodies in the 
rum lew. In the latter case we have, on the other hand, a 
on ition where the trypanosomes are few and the serum rich in 
anti-bodies. 
We have conducted experiments and used a so-called vaccine 
p pared at both the above stages. The first so-called vaccine was 
t 111 tr ' Vpanosomes ’ a °d was, therefore, more of the nature of a 
vaccin^T; 116 tJlan Iatter ’ w hich was what we might call a 
\ accine pl m an anti-serum. 
