350 CIRCULATION. 



diminution in the value of the ventricular systole of more 

 than one-half. 



In animals suffering under inflammatory fever, either 

 spontaneous or produced by irritants, the same observer 

 found a diminution in the rapidity of the circulation, accom- 

 panying acceleration of the pulse. In one observation, in- 

 flammation was produced in the horse by the injection of 

 ammonia into the pericardium. At the commencement of the 

 experiment, the pulse was from Y2 to 84 per minute, and the 

 duration of the circulation about 25 seconds. The next day, 

 with the pulse at 90, the circulation was accomplished in 

 from 35 to 40 seconds ; and the day following, with the pulse 

 at 100, the rapidity of the circulation was diminished to from 

 40 to 45 seconds. 



If we are justified in applying these observations to the 

 human subject (and there is no reason why this should not 

 be done), it is shown that when the pulse is accelerated in 

 disease, the value of the contractions ' of the heart, as rep- 

 resented by the quantity of blood discharged, bears an 

 inverse ratio to their number; and is so much diminished 

 as absolutely to produce a current of less rapidity than 

 normal. 



With regard to the relations between the rapidity of the 

 heart's action and the general rapidity of the circulation, the 

 following conclusions may be given as the result of experi- 

 mental inquiry : 



1. In physiological increase in the number of beats of the 

 heart, as the result of exercise, for example, the general circu- 

 lation is somewhat increased in rapidity, though not in pro- 

 portion to tJie increase in the pulse. 



2. In pathological increase of the heart's action, as in 

 febrile movement, the rapidity of the general circulation is 

 generally diminished, it may ~be, to a very great extent. 



3. Whenever the number of beats of the heart is consider- 

 ably increased from any cause, the quantity of blood dis- 

 charged at each ventricular systole is very much diminished, 



