328 



Addis 



film, a JsTge communication exists between the inner chamber and the air 

 of the room. The temperatures at which Buckmaster (28) worked varied 

 between 30° and 40° C. This is so much removed from room temperature 

 that there must necessarily be a rapid fall whenever the loop is removed. 

 When the opening is closed again by the reposition of the wire the tempera- 

 ture rises again. 



I further found it impossible to heat the water with a spirit-flame o;- a 

 gas-jet so as to keep the temperature constant, and the effect of an access 

 of heat to the water is not at oace apparent in the inner chamber where 

 th'^ thermometer is placed, so that one is constantly at fault in attempts at 

 regulation. 



By making a considerable number of observations and picking out those 

 which chanced to have been taken at the same temperature, some idea oi 

 the amount of variation due to other causes than temperature was obtained. 



There are thus considerable variations even when the temperature is 

 constant. 



I think that this inconstancy in my results was due to differences ol 

 thickness of film. After the loop is filled with blood a shake is given to it 

 in order to detach part of the blood- Unless this is done the film is so 

 opaque that it is difficult to see the streaming of the corpuscles. I did not 

 nay particular attention to the amount I shook off, and some of the films 

 were nnich thicker than others. 



When very thick and very thin films are compared at low temperatures 

 so as to give long coagulation times, there was found to be an enormous 

 difference in the time. 



