1873.] 



on the Temperature and Circulation. 



S77 



form of the tracing at the same time, that will enable us to judge how 

 the heart and its vessels will bear the strain of fatigue or of disease. One 

 heart may possess much more reserve force than another, and be able to 

 put forth an increase of energy under the very trial to which the other is 

 succumbing. One man's arteries may possess much more tone and his 

 capillaries more retentive power than another man's. 



The Temperature observations are very accordant, showing a rise of 

 •2° C. (-36° F.) in I. and IV., of -3° C. (5-°4 F.) in VII., of -4° C. (-72° F.) 

 in V. and IX., of -5° C. (-9° F.) in XI. and XIII., of -6° C. (1°-1 F.) in 

 VI., VIII., and X., and of 1° C. (1°«8 F.) in III. and XII. The general 

 result favours the view that the nerve-centres, which regulate tempera- 

 ture, are enfeebled, though but moderately, by the expenditure of force. 

 The degree of paresis produced varies much in different individuals ; but 

 only in two of my subjects did it approach the verge of morbid. The 

 cases, however, previously cited from Wunderlich, Obernier, and Wood- 

 man make it very probable that the same cause acting during a longer 

 time would have produced in my instances also decided febrile pheno- 

 mena ; in fact it must be considered remarkable that, in spite of the free 

 sweating which took place, the cool weather, and the lapse of some 

 minutes which occurred before the temperature could be taken, the rise 

 should have been so constant. One remarkable exception, indeed, there 

 is in case II., where the exertion produced actually a fall of -6° C. 

 (l o, 08 F.). This might be explained, as the individual is a man of fine 

 physique, by a similar assumption as was made with respect to the in- 

 crease of cardiac force, viz. that the regulating centres were stimulated 

 and not depressed by the exertion ; but this is doubtful, and I can find 

 no satisfactory explanation. In observation A, at the end of the walk 

 (twenty-two miles) the temperature was notably depressed, being no 

 more than 35°*4, i. e. l°-2 C. (2°-16 F.) below the ordinary temperature of 

 the individual. As food had been taken five hours before, lack of fuel could 

 hardly have been the sole cause, as it seems to have been in Dr. Clifford 

 Allbutt's case ; in fact the individual referred to has a temperature of 

 36°-2 C. (97°*16 F.) after six hours' fast, when quiescent. The tracing, 

 observation A (6), was small, but the circulation was fairly good, and the 

 walker did not feel at all chilled. The contrast in this instance between 

 the effects of short but severe exertion and prolonged moderate exertion is 

 very marked. The former raised the temperature of the same man on one 

 occasion -6° C. (l°-08 F.), the latter depressed it just twice as much. 



The Pulse-rate was doubled or more in II., IV., and V., and increased 

 to a less amount in the others. The reason usually assigned for this ac- 

 celeration, viz. that the blood arrives in greater quantity at the heart 

 because of the pressure exerted on the veins by the contracting muscles, 

 appears to me by no means satisfactory ; for if this were the real cause, 

 the heart's action ought to be equally accelerated, or nearly so, in all 

 persons, irrespective of their vital condition. Such, however, is by no 



