226 Proceedings of Philosophical Societies. [March, 



In the conclusion deduced from the whole, that part of 

 the heat which belongs to the light is shown to be de- 

 rived from the hot body, and to be abstracted or made to dis- 

 appear from its sensible temperature, so as not to be given off 

 as radiant heat. We have no right to assume that this portion 

 of the heat is converted into light. But it is evident that it 

 exists in some state of very close combination with light ; it is 

 never rendered sensible till the hght is absorbed, as by dark 

 coloured bodies. All bodies become luminous by the applica- 

 tion of a certain degree of heat. We can then form no other 

 conclusion, than that the portion of the heat which is in the 

 first instance lost, is, in fact, communicated in some way 

 to the light, and this can be in no other way than by becoming 

 latent in it ; and in fact thus giving it the form of light ; from 

 which it is again given out and rendered sensible when the light 

 is absorbed, or changes its state and enters into combination 

 with other bodies. 



This view of the subject is applicable to a variety of phaeno- 

 mena. Those of phosphorescence (hitherto considered so ano- 

 malous) are noticed. Most others are too obvious to require parti- 

 cularizing. 



These conclusions will perhaps be regarded as arguments in 

 favour of the materiality of light, it being thus shown to pos- 

 sess those properties in respect to latent heat, which would 

 belong to a substance of immense tenuity and elasticity. 



Feb. 24. — The reading was commenced of a paper, On the 

 Materno-foetal Circulation ; by David Wilhams, MD : commu- 

 nicated by Dr. John Thomson, of Edinburgh, FRS. 



: LINNEAN SOCIETY. 



The sittings of the Linnean Society for the Session 1824-5, 

 were resumed on Nov. 2, when the following papers were read : 

 ^ A letter from Mr.J. De Carle Sowerby, FLS. to Mr. R. Taylor, 

 Sec. LS. stating that many specimens of a fresh-water shell, 

 the mytilus polymuiphiis of Gmelin, which is a native of the Da- 

 nube, had been found attaclied to timber in the Commercial 

 Docks, where the species had probably been brought in timber. 



A Description of three Species of British Birds, two of them 

 new to the Ornithology of the British Isles ; by N. A. Vigors, 

 Juu. Esq. AM. FLS. : communicated by the Zoological Glub. 

 The birds described in this paper are, Ahthus Richardi, Vieillot, 

 "two specimens of which were taken a few years ago at Kings- 

 land, near London ; an undescribed Scolopax shot in Queen's 

 County, in Ireland, in 1822, and named by Mr. Vigors, S. Sa- 

 bmi ; and Querfjnedula glocitans, or the Bimaculated Duck, 

 taken in a decoy near Maldon within these few years. 

 • • A Description of Covania, a new genus of plants ; and of 

 a new species of Sieversia; by Mr. D. Don, Librarian -to the 

 Linnean Society. Tiiese remarkable plants, belonging to the 



