184 Royal Society. 



received opinion, the temperature of the human body, as mea- 

 sured by a thermometer placed under the tongue, is not a constant 

 one, the author has resumed the inquiry, and gives, in the present 

 paper, the results of numerous observations made with a particular 

 instrument constructed for the purpose, admitting of minute accu- 

 racy (each degree of the scale being divided into ten parts), and 

 when used with the precautions pointed out, affording satisfactory 

 indications of the many problems which may be proposed relative to 

 the temperature of man, &c., confining himself to a small number, 

 and offering the information he brings forward only as a preliminary 

 contribution in aid of their solution. 



The paper is divided into seven sections. 



The first treats of variations of temperature during the twenty-four 

 hours. The author finds from his observations, that the temperature 

 is highest in the morning, on rising after sleep ; that it continues 

 high, but fluctuating, till the evening ; and that it is lowest about 

 midnight, ranging on an average from 98*7 to 97*9. 



The second, of variations during the diff'erent seasons. These, he 

 finds, bear some relation to the temperature of the air, but less than 

 might be expected ; which he attributes to the majority of the ob- 

 servations having been made within doors, under circumstances pe- 

 culiarly favourable to uniformity. 



The third, of the influence of active exercise on the temperature. 

 The effect of this, when not carried to the length of exhausting fa- 

 tigue, he finds to be elevating ; and that the augmentation is, within 

 a certain limit, proportional to the degree of muscular exertion. 



The fourth, of passive, such as carriage exercise. The effect of 

 this in a cool air, contrary to that of quick walking or riding, would 

 appear to be lowering. 



The fifth, of abstinence from all exercise in a cold atmosphere. 

 This he finds to be depressing in a still greater degree ; sitting in a 

 cold church has occasioned a reduction of temperature from 1° to 

 2°, the air of the church being from 42° to 32°. 



The sixth, of sustained attention or exertion of mind. This would 

 appear to have the effect of raising the temperature, but in a much 

 less degree than bodily exercise. 



The seventh, of taking food. It would appear that a light meal, 

 such as breakfast, alters very little the temperature, whilst a heavy 

 meal, such as dinner with wine, tends to lower it. 



The conclusion drawn by the author from his observations, con- 

 sidered in their greatest generality, is, that the temperature of man 

 is constantly fluctuating within a certain limit, regularly during 

 the twenty-four hours ; and irregularly according to the operation 

 of certain disturbing circumstances. 



Should multiplied observations give similar results, he infers that 

 they will admit of many applications, both as regards the regulation 

 of clothing, the warming of apartments, and it may be the preven- 

 tion and cure of diseases, — conducive alike to increase of comforts 

 and health. 



Tables are appended containing a series of observations extend- 



