ACTION OX PULSE RATE. 47 



reduces the number of beats without rendering tlieni irregular. 

 If its influence be pushed farther, tlie pulse remains slow, but 

 now and then a quick beat is interpolated.* These quick beats, 

 as the influence increases, become more numerous, so that the 

 slow beats which now occur only occasionally become inter- 

 missions ; and in a still further stage, the slow boats entirely 

 disappear, and the pulse becomes regular and extremely rapid. 



This slowing, intermission, and flnal rapidity have been fre- 

 quently examined in animals, and thoiigii I ani not aware that 

 the gradual succession of the quick beats to the slow, whicli 

 occasions the intermittence, has been shown, probably from the 

 readiness with which it would escape the observation of the 

 finger, though at once detected by the eye, yet w^e see it with 

 great clearness in the case of Daniel G., and though this was- 

 not during the increase but the decrease of the symptoms, T 

 think we may infer tliat these came on very much in the same 

 order in which they went off. 



Some have held that there is an acceleration of the pulse- 

 before the retardation appears. Bouley and Keynalf noticed 

 this in horses poisoned with large or moderate doses, but. never 

 observed it after therapeutical doses had been given. The 

 doctrine of primitive acceleration from medicinal doses was 

 advanced by Sanders.J and supported by Joerg§ and Hutchin- 

 son.|| This acceleration is of two kinds — 1st, following- 

 on the administration of digitalis, and disappearing, or at least 

 diminishing, mucli within half-an-hour or three (juarters ; and 

 2nd, a more permanent acceleration lasting for 24 to 48 hours 

 or longer : the effect of the temporary acceleration not passing 

 (juite away during the interval between the doses, so tliat each 

 succeeding one raises the pulse a little higher than before, till 

 at last the acceleration gives place to retardation, and the 

 number gradully falls, passing even below^ the normal standard. 

 Though Sanders adduced 2,000 observations in support of his 

 view, yet most succeeding authors have denied it. I have 



* Case of Daniel Or. t Op. cit. 



X Sanders, ' On Fox/jlore.' 



§ Joerg, Arch, de Med., prem. ser., tome xxvii, p. 107 (II. and Q.)» 



il Hutchinson (II. and Q.). 



