CHAPTER III. 



DIFFERENT TIMES IN BLOODLETTING ; OF THE STOPPING OF 

 HEMORRHAGES; AND OF THE EFFECTS OF COLD UPON THE 

 BLOOD. 



* 



IT has been observed by those who have written on the 

 blood, that it sometimes happens in bloodletting, that the first 

 cup has an inflammatory crust, whilst the last has none ; but no 

 satisfactory reason has been given for this difference. One 

 might suppose that it was owing to some circumstance in the 

 bleeding, such as in the different velocity with which the blood 

 flowed into each cup, or to the last cup's being agitated so as 

 to prevent the separation of the lymph : but I have seen it 

 where there was no difference of this sort, nor in any other cir- 

 cumstance that I could observe. I therefore suspect that in 

 such cases the properties of the blood are changed, even during 

 the time of the evacuation ; to which opinion I was led by the 

 following experiments. 



EXPERIMENT XIX. 



Nine ounces of blood were taken from a woman who had 

 been delivered two days before, and who at that time laboured 

 under a fever, with a considerable pain in her side and in her 

 abdomen. The blood was received into a basin, and her arm 

 was tied up ; when, on looking at the blood, I found its surface 

 v transparent for some depth, an indication of a future crust ; 

 and as her pain was not abated, and as her pulse could bear 

 it well, I removed the ligature from her arm, and took away 

 about six ounces more, into three teacups; but what appeared 

 to me remarkable, although the blood flowed as fast into each 

 of the cups as into the basin, and when full they were imme- 

 diately set down on the same window, yet there was no iiiflam- 



