564 



tion between them of interstitial matter, and also by the cleavage of 

 the latter and the consequent multiplication of the granules. This 

 peripheral growth of the cells is totally different from the mode of 

 growth described by Schwann, and explains the disappearance of the 

 nucleus in the scales of the epidermis. The observations of the 

 author lead him to believe that the same process of development and 

 of growth is followed in the epithelium as in the epidermis ; and he 

 offers evidence, showing that similar arrangements take place in the 

 cells of melanosis, in the pigment cells of the choroid membrane of 

 the eye, and in those of the skin of the negro. 



" On the Temperature of Man." By John Davy, M.D., F.R.S. 

 L. & E. 



Having in a former paper shown that, contrary to a commonly 

 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 in many problems which may be proposed relative to the 

 temperature of man. See., and confines himself to a small number, 

 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 different 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. 



