138 Proceedings of Philosophical Societies. [Feb. 



Dr. Davy has found the skin of the Toad to contain pores of 

 two kinds ; the larger, chiefly confined to particular situations, 

 and which, when the skin is held up to the light, appear as 

 iridescent circles, and the smaller, more numerously and gene- 

 rally distributed, which appear as luminous points of a yellowish 

 colour. Externally these pores are covered with cuticle, and 

 some of the larger ones even with rete mucosum ; internally 

 they are lined with delicate cellular tissue. By inflating the 

 skin. Dr. D. ascertained that it was not furnished with spira- 

 cula, the existence of which he had been led to suspect by some 

 particular circumstances in the physiology of the animal. 



A paper, by the same author, was also read, On the Heart of 

 Animals belonging to the Genus Rana. Dr. Davy has discovered 

 that the heart of the Common Toad, the Bull Frog, and the Com- 

 mon Frog, instead of consisting of one auricle and one ventricle, 

 as generally stated, has two auricles, divided by a septum of 

 fibrous substance ; and he has reason to believe that this struc- 

 ture prevails throughout the order o{ Batraciens. This discovery 

 removes the anomaly among Reptiles supposed to be presented 

 by these animals, as forming a portion of the link between 

 Mammifera and Fishes, and preserves unbroken the chain of 

 connection between Reptiles and Fishes arising from the analogy 

 of their respective organs of respiration. 



Jan. 12, 1826.— Dr. T.S. Tiarks, and Sir C. Wetherell, Knt. 

 his Majesty's Solicitor-General, were respectively admitted 

 Fellows of the Society. 



A paper was read, entitled, " Observations on the Heat of 

 July, 1825, together with some Remarks on sensible Cold; by 

 W. Heberden, MD. FRS." 



These observations were made on the author's lawn at Datchet, 

 in Berkshire, by means of thermometers suspended in the shade 

 of trees : the highest temperature observed was 97° Fahr. Dr. 

 Heberden remarks, that the extraordinary weather of this month 

 passed away without rain, lightning, change of wind, or any 

 other obvious cause ; and cites the nearly parallel case of the 

 year 1808, as recorded in the Society's observations, and also 

 by Mr. Cavendish. He gives some observations and experi- 

 ments on a method of ascertaining the sensible heat, which he 

 believes to be much above that indicated by the thermometer, 

 by means of previously raising the thermometer to a high tem- 

 perature, and then noting its successive decrements in equal 

 times on exposing it to the open air. In the concluding 

 remarks on sensible cold, Dr. H. states his opinion that its chief 

 cause is the loss of heat by the body effected by the action of 

 the wind, not by the moisture of the surrounding atmosphere. 



A communication was also read, entitled, " An Account of a 

 Series of Observations to determine the Difference of Longitude 

 between the National Observatories of Greenwich and Paris ; by 



