50 Royal Society. 



they present some remarkable peculiarities. In conducting these in- 

 quiries he obtained, through the favour of Colonel Colby, R.E., and 

 Lieut. Yelland, R.E., the able assistance of non-commissioned officers 

 and privates of the corps of Royal Sappers and Miners. He explains 

 in detail the nature of his observations, and the method he pursued 

 in constructing tables of mean results ; and deduces from them the 

 conclusion, that the peculiarities in the tides which are the object of 

 his investigation are not dependent on any variations in the state of 

 the atmosphere, but are probably connected with the laws which 

 regulate the course of waves proceeding along canals. 



2. A paper was in part read, entitled, " On the Special Function of 

 the Skin." By Robert Willis, M.D. Communicated by John Bos- 

 tock, M.D., F.R.S. 



March 9. — 1. The reading of a paper, entitled, " On the Special 

 Function of the Skin." By Robert Willis, M.D. Communicated 

 by John Bostock, M.D., F.R.S., was resumed and concluded. 



The purpose which is answered in the animal economy by the cu- 

 taneous exhalation has not hitherto been correctly assigned by phy- 

 siologists : the author believes it to be simply the elimination from 

 the system of a certain quantity of pure water, and he considers that 

 the saline and other ingredients which pass off at the same time by the 

 skin are in too inconsiderable a quantity to deserve being taken into 

 account. He combats by the following arguments the prevailing 

 opinion, that this function is specially designed to reduce or to regu- 

 late the animal temperature. It has been clearly shown by the ex- 

 periments of Delaroche and Berger, that the power which animals 

 may possess of resisting the effects of a surrounding medium of high 

 temperature is far inferior to that which has been commonly ascribed 

 to them ; for in chambers heated to 120° or 130° Fahr., the tempe- 

 rature of animals is soon raised to 11° or even 16° above what it had 

 been previously, and death speedily ensues. The rapid diminution 

 or even total suppression of the cutaneous exhalation, on the other 

 hand, is by no means followed by a rise in the temperature of the 

 body. In general dropsies, which are attended with a remarkable 

 diminution of this secretion, an icy coldness usually pervades both 

 the body and the limbs. A great fall in the animal temperature was 

 found by Fourcauld, Becquerel and Breschet to be the effect of 

 covering the body with a varnish impervious to perspiration ; and 

 so serious was the general disturbance of the functions in these cir- 

 cumstances, that death usually ensued in the course of three or four 

 hours. 



The question will next arise, how does it happen that health and 

 even life can be so immediately dependent as we find them to be on the 

 elimination of so small a quantity of water as thirty-three ounces from 

 the general surface of the body in the course of twenty-four hours ? 

 To this the author answers, that such elimination is important as 

 securing the conditions which are necessary for the enclosmotic trans- 

 ference between arteries and veins of the fluids which minister to 

 nutrition and vital endowment. It is admitted by physiologists that 

 the blood, while still contained within its conducting channels, is 



