June 17, 1825] 



NATURE 



133 



sents the average temperature of his own body at the 

 different hours of the day, in order that he might ehmi- 

 nate this factor as a disturbing cause in his special obser- 

 vations. The curve represents an elevation of the 

 temperature between the hours of 3 and 9 a.m., and a fall 

 between 9 p.m. and 2 A.M., with an elevated temperature 

 during the day, the undulations of which are far from 

 constant and are difficult to characterise. In employing 

 these results practically, Dr. Forel has introduced a 

 method of turning them to account, which is as useful as 

 it is precise and ingenious. In any special experiment, 

 calling t the temperature, and T the normal temperature 

 at the time of observation as found from the tabulated 

 curve, then 



• t- T= f 

 i' being the difference between the observed temperature 

 and that which, under ordinary circumstances, it would 

 be, either above or below it. As examples, we will take 

 two given by the author : — 



At 12 o'clock, noon, T = 9909° F. On one particular 

 occasion / was found to be 99*5° F., and therefore 

 /- T=t' = +0-41° F. 



On a secord occasion, at the same time of day, the 

 temperature observed was 9878° F., from which it is 

 evident that 



/' = — o'3i. 



By the employment of this very simple means, there- 

 fore, the ccmplications dependent on the time of day at 

 which an observation is made may be immediately eli- 

 minated ; all comparisons being between the different 

 values of /', and not of /. Whether the assumption that 

 the daily curve of body-temperature-change depends on 

 the time of the day at which the observation is made, and 

 on the time only, is a question into which the author does 

 not enter, notwithstanding that such is the case has been 

 by no means proved. 



Turning now to the results arrived at from the investi- 

 gation, the position in which the subject was left by 

 Marcet and Lortet may be thus summarised : — 



1. The temperature of the body, as a rule, falls during 

 the act of ascending an incHne. 



2. During the time of the " mountain sickness," which 

 so frequently accompanies the ascent of lofty heights, the 

 body-temperature falls in a very marked manner. 



Dr. Forel's earlier experiments, conducted in 1871, in 

 which the thermometer was retained in the mouth, as was 

 done by Marcet and Lortet, being directly opposite in their 

 tendency, led him to commence the whole subject in 1872, 

 as he remarks ab ovo, under his improved conditions. 



As to the effect of an uncomplicated ascent, two in- 

 stances are given in full, in both of which a consider- 

 able rise in temperature accompanied a rapid ascent of 

 about an hour's duration. In one of these, at the end of 

 the journey, the thermometer registered 102-5° F., whereas 

 it was slightly below 100° F. on starting. 



In a second series, three illustrations are given of the 

 effect of well-marked fatigue, just short of exhaustion. 

 The following are the deductions drawn from them : — 



1. Even in conditions of great fatigue, the human body 

 rises in temperature upon the muscular effort of ascending 

 a height. 



2. It is impossible for the author to determine if the 

 elevation of animal heat due to the movement of ascension 

 diminishes in proportion to the increase of the muscular 

 fatigue. 



Next as to the influence of an empty stomach on the 

 temperature curve ; and it must be noted, with regard to 

 this point, that both Marcet and Lortet have stated that 

 the fall in temperature accompanying an ascent is more 

 marked during a fast than shortly after a meal. On him- 

 self. Dr. Forel, however, again proves that a fast of twelve 

 or even twenty-four hours is no obstacle whatever to the 

 rise of temperature which attends the muscular effort of 

 ascending a hill. 



By collecting and comparing the temperature-curves 

 produced in ascending and descending inclines, the author 

 is enabled to verify the theoretical necessity that the body- 

 temperature is raised more by a descent than by an ascent. 

 From twenty-one experiments, the average rise in tempe- 

 rature attending the act of ascending is found to be 

 2'4i2° F., whereas the mean of seven descents is found to 

 be 2772° F. The difference, o'36° F., is small, it is true. 

 If this fact is reliable, we find that a certain amount of 

 heat is transformed into mechanical work during the act 

 of ascent, a certain quantity being returned to the organism 

 from without, under the opposite condition. 



There are several minor points which Dr. Forel dis- 

 cusses in a particularly instructive manner, amongst 

 which are the time of cooling after muscular exertion, the 

 effect on the pulse and respiration of mountain climbing, 

 and the cause of mountain sickness. He terminates his 

 very interesting observations by the account of an ascent 

 of Mont Rosa in July 1873 (15,217 feet), in which, not- 

 withstanding that he suffered from mountain sickness, 

 the body-temperature never showed any tendency to fall 

 throughout, and was ioi*5° F. on his reaching the highest 

 point. 



From this summary of Dr. Forel's results, when taken 

 in connection with those of Dr. Allbutt,* it is evident that 

 the temperature-fall observed by Drs. Marcet and Lortet 

 during mountain climbing requires re-verification, and 

 cannot be accepted as a physiological fact until a fallacy 

 has been shown to exist in the method of investigation 

 adopted by the Swiss experimenter. A. H. G. 



NOTES 



At Cairo, on the 2nd inst., the inaugural meeting took place 

 of the Societe Khtdivale de Geographie, tender the presidency 

 of the eminent traveller Dr. Schweinfurth and the patronage 

 of H.H. the Khedive, who has shown special favour to the 

 young society, having placed at its disposal a handsome suite 

 of apartments furnished in suitable style, and also pre- 

 sented a valuable library, besides subscribing 400/. a year to the 

 funds. This cannot but be gratifying to the friends of science 

 and progress, and is a hopeful sign for the future of Egypt and 

 of the extensive region from which it claims allegiance. Let us 

 hope that like results will follow the , intercourse between this 

 country and the Sovereign of Zanzibar. With these two African 

 potentates on the side of progress, the advantages to knowledge, 

 as well as to Africa, could not but be great. At all events, 

 under the powerful patronage of the Khedive, this Egyptian 

 Geographical Society is bound to make valuable contributions to 

 our knowledge of North Africa. Dr. Schweinfurth, in his 

 inaugural address, which was characterised by great fervour, 

 spoke of the domain and progress of geography. "It has 

 become," he said, "an immense domain, the meeting-place of all 

 branches of human science. The geography of the present does 

 not aim at merely describing the external form of the earth, the 

 vesture which it has assumed ; it seeks to show the chain of 

 hidden causes of which this form is the expression." lie then 

 spoke of Africa and the great interest attaching to it, and espe- 

 cially to the Nile, the sources of which he believes contain the 

 key to all the mysteries of Africa. Dr. Schweinfurth then 

 referred to the history of Egypt and its progress under its present 

 ruler, by whose special desire the Society has been organised. 

 The motto of the Society, he said, should be Nusquam otiosus, 

 and its duty CentraUur et encourager. After pointing out to 

 those who take a "utilitarian" view of science, that all the 

 comforts and commodities of modern hfe are due to researches 

 which, though purely theoretical in their origin, have yielded 

 magnificent practical results, Dr. Schweinfurth indicated the 

 benefits to be gained from the increase of geographical know- 

 • y our ttal 0/ Anatonty attd Physiology, yo\. xi. p. io6. 



