254 PSYCHOLOGICAL EFFECTS OF ALCOHOL. 



"In the course of experiments it has been observed that with very slight 

 activity the pulse and the metabolism are at a minimum. When the activity 

 is increased, the pulse-rate is likewise accelerated, and there is an increase in 

 the total metabolism. It has furthermore seemed clear that the increase 

 in the pulse-rate is relatively proportional to the increase in the actual mus- 

 cular activity observed." (Benedict and Carpenter. 1 ) Again (p. 249) : 

 "Pulse-rate increases during the waking hours of the day as compared with 

 the night. We can obtain an approximate idea of the total metabolism from 

 the pulse-rate of a subject, although the rate per minute of itself is not neces- 

 sarily a general index of the katabolism for all individuals." 



Still more recently Murlin and Greer 2 wrote: 



"Experiments on dogs were devised in which the absorption of oxygen and 

 the output of carbon dioxide were determined by means of a small Benedict 

 respiration apparatus attached directly to the dog's trachea. Simultaneously 

 the blood-pressure was recorded. The effects of anesthesia were controlled. 

 Similar experiments on several different men in widely different nutritive 

 conditions and in varying degrees of muscular activity (lying on a bed, stand- 

 ing, standing and lifting weights, shivering, etc.) were also done by means of 

 the same respiration apparatus and the Erlanger sphygmomanometer. The 

 results show a fairly close correlation in the same individual between the heart- 

 output expressed as the product of the pulse-pressure and the heart-rate on 

 the one hand, and the absorption of oxygen and the elimination of carbon 

 dioxide on the other. The relation between carbon-dioxide elimination and 

 heart-action is on the whole a little more constant than that between the 

 oxygen absorption and heart action." 



Quite recently observations by Professor H. M. Smith, of the Nutri- 

 tion Laboratory, have shown that during walking the metabolism may 

 increase 250 per cent without any increment in pulse-rate. This 

 striking exception to the rule makes us very cautious in drawing unsup- 

 ported inferences from the pulse-rate to metabolism, in spite of the 

 fact that all the other experience of the Laboratory is to the effect 

 that increased muscular activit} r correlates with an increased pulse. 



The existence of some intimate connection between pulse and mental 

 states is a commonly accepted fact of great antiquity. Mosso 3 and 

 his followers found in the relative distribution of the blood to the brain 

 and other parts of the body a measure of mental activity. Seriously 

 controlled attempts to correlate definite circulatory changes with defi- 

 nite mental processes find their most important expression in the work 

 of Lehmann. 4 An enormous amount of data still leaves the question 

 open whether any specific mental state can be absolutely correlated 

 with any specific change in pulse or respiration, in the sense that the 

 one can be inferred from the other. Indeed, in our knowledge of the 

 nervous conditions of vasomotor inner vation there seems to be no good 

 reason for definite correlation with specific cerebral processes. That 



1 Benedict and Carpenter, The Metabolism and Energy Transformations of Healthy Man 

 during Rest, Carnegie Inst. Wash. Pub. No. 126, 1910, p. 248. 

 2 Murlin and Greer, Am. Journ. Physiol., 1910-11, 27, p. xviii. 

 3 Mosso, Ueber den Kreislauf des Blutes im menschlichen Gehirn, Leipsic, 1881. 

 *Lehmann, Die korperlichen Aeusserungen psychischer Zustande, Leipsic, 1899-1905. 



