62 PROPERTIES OF 



in the third cup was thirty-five minutes in being completely 

 coagulated, whilst that in the fourth, although taken from the 

 arm only two minutes later, yet coagulated in three minutes. 

 Now no exposition to the air nor to cold, from the blood's 

 trickling down the arm, could produce such a change. Of this 

 I am persuaded from what I have observed on comparing the 

 blood received into a cup with that which dropped on the plate 

 which held the cup ; for I have repeatedly seen on those oc- 

 casions that the blood on the plate, although it was so much 

 more cooled and so much more exposed to the air than that in 

 the cup, yet instead of coagulating proportionably sooner, was 

 later in being coagulated. The following experiment shows this 

 clearly. 



EXPERIMENT XXXI. 



A young woman with a violent inflammation in her eyes, was 

 bled on the fifth of March, early in the morning, before she had 

 breakfasted, and whilst she was complaining of a sickness at her 

 stomach; the blood followed the lancet in a stream, but im- 

 mediately after it only trickled down the arm, and continued to 

 do so during the whole of the evacuation. About eight ounces 

 of blood were taken away into four vessels, viz., into two cups 

 and two saucers, in the following manner : A plate holding both 

 a cup and a saucer was held under the arm, and the blood was 

 first received into the saucer, to the quantity of a spoonful, then 

 as much more was received into the cup that stood by it ; 

 then again the blood was suffered to run into the saucer, and 

 afterwards into the cup, and so alternately till there was about 

 two ounces in each, when they were carefully set down on a 

 window where the thermometer stood at 57; the plate was 

 placed by them, and contained about a spoonful of blood, which 

 had missed the saucer in the begining of the evacuation. Next, 

 the second plate was brought, and some blood was received first 

 into the cup and then into the saucer, in the same manner ; 

 and three portions of blood were suffered to drop at different 

 times on the plate, each of them about the breadth of a shilling. 

 Now, here, according to the reasoning in the objections made 

 to some of the preceding experiments, the blood in the saucers 

 having twice as much surface as that in the cups, ought to have 

 coagulated in half the time ; and that on the plates ought, from 



