INFLUENCE OF TEMPERATURE ON THE 

 PULSATIONS OF THE MAMMALIAN HEART 

 AND ON THE ACTION OF THE VAGUS. 



(Reprinted from St. Bartholomew's Hospital Reports, vol. vii, 1871, 

 pp. 216 to 228.) 



The influence of warmth in quickening the pulse has been 

 long known, but the hypothesis put forward by Budge,* and 

 again by Liebernieister,t that the quickness of the pulse in 

 fever is due to the increased temperature of the body, gives 

 it an interest to physicians which it would not otherwise possess. 

 This hypothesis is grounded on the fact that increased tem- 

 perature, within certain limits, causes the hearts of frogs and 

 mammals to beat more quickly, both when they are in the body 

 and after they have been separated from it. This has been 

 observed in the frog's heart by Humboldt, J Pickford,§ Weber ,|| 

 Budge,ir Tigger,** Panum,tt Calliburces,tt Schelske,§§ and by 

 Cyon,|||| in Lud wig's laboratory. As the experiments of the 

 last-mentioned observer were more complete and extended than 

 those of the others, I shall give the results which he obtained. 

 His experiments were performed by removing the heart 

 entirely from the body of the frog, filling it with serum 

 through the vena cava, and connecting the aorta with a 

 manometer, by which tlie number and force of the pulsations 

 could be measured and registered. The heart was then enclosed 

 in a vessel wliose temperature could be altered at will. Any 



* Budfre, quoted by Panum. 



t LiL'beimeister, Deutsch. Arch. f. Jclin. Med., vol. i, 461. 



X Quoted by Panum. 



§ Pickfurd, Ilenle u. Pf. Zellsch., vol. xi, 2, 1851. 



II Weber, quoted by Panum. 



f Budge, Arch. f. phys. Hfilk, vol. v, 59:). 



** Tigger, Dissertation, 1853, quoted by Panum. 



ft Panum, BiUiotheJc filr Layer, Bd. x, p. 46, and Schmidt's Jahrl., 1858. 



XX Calliburces, Gaz. held., 1857, p. 468. 



§§ Solielske, TJeher die Verdnderung der ErregharJceit durch die Wdrme, 1860, 



jjlj Oyon, Ludicig's Arheiten, 1866. 



