Enquiry into the Heat given out by the Human Body. 251 



highest number and ending with the lowest, and also inscribing 

 opposite these figures those showing the oxygen absorbed in each 

 corresponding experiment, it would be expected that the figures for 

 oxygen absorbed would follow in succession those for the calories 

 found, beginning with the highest and ending with the lowest. 

 Such, however, is far from being the case. Therefore, except in a 

 very general way, as shown by our means and under similar circum- 

 stances with reference to food, the oxygen taken from the air 

 does not produce heat in the body in proportion to the amount absorbed. 

 And this may be taken as a clear indication that the oxygen absorbed 

 in a given time is not a measure of the heat produced during that 

 same time. 



Should tables now be made of the calories in numerical order, 

 beginning with the highest, placing the figure for " calories for 

 1 gram oxygen absorbed " opposite its respective calories, a peculiar 

 occurrence is observed. It will be seen readily by a consideration of 

 the foregoing tables that if the calories found in one hour and 

 those calculated for 1 gram oxygen absorbed be grouped three 

 by three (or even two by two), the calories for 1 gram oxygen 

 absorbed decrease fairly regularly together with the falling for the 

 hour-calories (less so when taken two by two), and this takes place 

 in the case of three different persons, and therefore cannot possibly 

 be accidental. It follows that 1 gram of oxygen absorbed from the 

 air is attended with the emission of either 5031 calories or 3292 

 calories, as extremes for one person, and for another person either 

 4455 or 3433 calories, and again for a third either 4126 or 3398 

 calories. The readiest explanation of this phenomenon is the assump- 

 tion of a storage of oxygen in the tissues, which is made use of, 

 although unaccounted for (as oxygen absorbed) at the time. Still, 

 the mean relation of the oxygen absorbed to the heat emitted remains 

 the same, being as nearly as possible 4000 calories for 1 gram 

 oxygen absorbed under similar conditions. 



This shows that whatever be the mode of action of the absorbed 

 oxygen it repeats itself in a general way, if taken at similar periods 

 with reference to food, &c. 



There is a circumstance in these experiments which should be 

 taken into account concerning the frequent change of temperature 

 of our bodies while in the calorimeter, as ascertained by sublingual 

 observations with a clinical thermometer. The cooling reached an 

 extreme of 0'45 C., though usually only 0'15 or 0'2 C., but it 

 varied much in different experiments, while on some occasions there 

 was no change, and even once or twice a rise was observed. The fall 

 of temperature was thought at first to be due to the proximity of 

 the ice in the chamber ; but the same effect was observed by taking 

 W. M.'s sublingual temperature while sitting quite quiet for an hour 



