224 Proceedings of Royal Society of Edinburgh, [march 5, 
case of exceptional cells may be so strong or so continued as to 
lead to an apparent or real breaking down, which occurs, however, 
only after, and sometimes long after, coagulation is complete. 
When removed from the body, of course all the cells eventually 
die. 
Inert Solids and their Action on Blood Plates. 
This subject was suggested by Professor Greenfield, and the work 
was done by his kind permission in his wards at the Eoyal Infirmary. 
We had also the advantage of the assistance of his demonstrator, 
Dr Gibson, who has made the blood plates a special object of 
study. 
In all these experiments the blood of patients suffering from 
chronic diseases was examined, as in these cases blood plates are 
more numerous than in healthy individuals. The method used was 
in all cases the one mentioned at the commencement of this 
communication. 
In all cases the blood was allowed to remain for about thirty 
minutes in the oil, after which it was placed in a slide in osmic 
acid, and examined with yV inch water immersion lens. The blood 
plates were found floating free in the fluid. They had not changed 
in any way. In drops of blood mounted fresh from the body, the 
blood plates ran together and changed their shape. 
Conclusion . — The action of an inert solid on blood plates is much 
the same as its action on white blood -corpuscles. It causes them to 
become sticky and to run together, lose contour, and change their 
shape. 
The life history of blood plates has certainly not been made out. 
They have been described as special and peculiar elements of the 
blood, but their origin and ultimate destiny have never been 
explained. They appear to be simply bits of protoplasm like 
white blood-corpuscles, both from their appearance and their under- 
going similar changes on irritation. 
These changes which we have described are the morphological 
changes which occur in the blood during coagulation. These 
experiments do not in any way determine the part played by the 
white corpuscles and so-called blood plates in the chemistry of 
coagulation. 
