1888.] Messrs Haycraf t & Carlier on Morphological Changes, 221 
by solid matter. Dr Freund and Professor Hay craft* have advanced 
further proof of the correctness of this view. 
The exact action of a chemically inert solid, such as glass, in 
producing coagulation remains an undetermined point. This we 
have resolved to investigate, and have introduced to the Society at 
a recent meeting a method by means of which experiments may be 
made with human blood. 
When a drop of blood is allowed to flow into oil, and another 
drop, for purposes of comparison, is received on to a glass slide, the 
former will not clot ; the latter will clot in from five to ten minutes. 
If, on examination of the two drops, any difference in the blood-cells 
is visible, it must be due to absence or presence of solid matter. This 
leads us to consider the action of inert solids on blood-corpuscles. 
Action of Solid Matter on White Blood-Corpuscles. 
There are at least two sorts of white blood-corpuscles in circu- 
lating blood. Both these kinds when in the circulation are rounded 
in shape, exhibiting no amoeboid movements except in diapedesis. 
If human blood be received on a slide at a temperature below 
65° F., the white corpuscles remain rounded; if the temperature be 
elevated to about 68° F., they soon exhibit movement ; if a tempera- 
ture of 74° F. be attained, they become very active. 
Experiments. 
Temperature of room and oil, 70° F. 
A drop of blood was received from a well-greased finger into a 
tube full of pure castor oil, in which it could be kept free from solid 
matter; another drop was received on a clean slide, where it coagulated 
in about ten minutes. This was examined before coagulation had 
begun, and the white corpuscles were seen to be actively amoeboid, 
their movement continuing even after the field of the microscope 
was thickly covered with fibrin threads. At the end of thirty 
minutes the blood was removed from the oil, placed upon a clean 
slide, and examined. The white corpuscles were all globular, but 
after two or three minutes they began to show amoeboid move- 
ments. 
* “An Account of some Experiments, which show that Fibrin Ferment is 
absent from circulating Blood Plasma,” Proc. Roy. Soc., July 1887, and Jour. 
Anat. and Phys., vol. xxii. 
