endotoxins. He was good enough to prepare it for us by injecting 
Mellin’s food into the pleural cavities of rabbits. The rabbits were 
then killed, and the accumulation of leucocytes taken from the 
pleural cavity, and extracted with sterile distilled water. 
I o our surprise, the effect of an injection of this leucocytic 
extract was to produce a very great increase of leucocytes in the 
blood on the day following the injection. This was almost the 
invariable result. In our opinion, it seems to be a far more 
powerful promoter of leucocyte increase than yeast or nuclein. 
We tried to utilise this discovery in two ways: — 
(i) To help the natural leucocyte increase by injecting the 
extract just at the height of the trypanosome rise. We did this 
on May 19. Next day, as we have mentioned, the patient showed 
<1 remarkable improvement. We were unable, however, to get such 
a happy result again. 
(ii) By injecting the extract a day or two before the rise of 
parasites, we thought we might prevent that rise by causing an 
early increase in the leucocytes. 
On May 31 10 c.c. of the extract were injected, producing next 
day an increase of leucocytes up to 20,000 per cubic millimetre of 
blood, but they diminished next day to 2,800 per cubic millimetre, 
and the increase of trypanosomes occurred all the same. 
Later, just before the patient’s death, we tried the effect of 
c.c. doses of the extract daily. This seemed to keep the leucocyte 
count high, but unfortunately the results were complicated by the 
patient developing an abscess at this time, and later by the 
development of pleuro-pneumonia. 
1 uither investigation with this substance, and with vaccine, 
° U ^ . re puire to be made before coming to any definite 
conclusions. Such an investigation we think would lead to further 
now ledge regarding the natural balance of immunity between the 
body and the parasites. 
It app ears to be a law (at least it seems to hold good, we think, 
at 1 eucocytes and trypanosomes) that the extract of dead animal 
timulates the corresponding live cells to increase in numbers. 
UOU ^ a Ppeai to support the hypothesis put forward by 
r ’,.. ' R° ss > that the extracts of dead tissues promote the 
Proliferation of living cells.* 
’ Rnt. Med. Journ.. June 11, i 9 , 0 . “ “ 
