AN ANATOMICAL STUDY ON THE 



diastole, contains two or three ounces, or only an 

 ounce and a half. In a cadaver I have found it 

 holding more than three ounces. Likewise let us 

 consider how much less the ventricle contains when 

 the heart contracts or how much blood it forces 

 into the aorta with each contraction, for, during 

 systole, everyone will admit something is always 

 forced out, as shown in Chapter III, and apparent 

 from the structure of the valves. As a reasonable 

 conjecture suppose a fourth, fifth, sixth, or even 

 an eighth part is passed into the arteries. Then 

 we may suppose in man that a single heart beat 

 would force out either a half ounce, three drams, 

 or even one dram of blood, which because of the 

 valvular block could not flow back that way into 

 the heart. 



The heart makes more than a thousand beats in 

 a half hour, in some two, three, or even four thou- 

 sand. Multiplying by the drams, there will be in 

 half an hour either 3,000 drams, 2,000 drams, five 

 hundred ounces, or some other such proportionate 

 amount of blood forced into the arteries by the 

 heart, but always a greater quantity than is pres- 

 ent in the whole body. Likewise in a sheep or dog, 

 suppose one scruple goes out with each stroke of 

 the heart, then in half an hour 1,000 scruples or 

 about three and a half pounds of blood^ would be 



^ The Apothecaries or Troy weight is used: 3 scruples equal i 

 dram; 8 drams equal i ounce; 12 ounces equal i pound. This was in 



I74I 



