Chemical Society. 385 



veying to the mind the perception of the motions of the limbs and 

 of their different parts. He concludes with some remarks on the 

 double crossings of the tracts of the centres of the nerves of the 

 arms and legs, and the explanation given by these facts to various 

 pathological phenomena. 



7. " Nouveaux faits a ajouter a la Theorie de la Chaleur et a celle 

 de l'Evaporation." Par Daniel Parat, Medecin a Grenoble. Commu- 

 nicated by the President. 



The author commences by explaining his conception of the nature 

 of heat, of which he gives the following definition : — " Mouvemens 

 centraux obsculaires de la cohesion devenus extemporanement plus 

 rapides, et dilatant de plus en plus tous les corps par une augmenta- 

 tion ainsi acquise de toutes les forces centrifuges." He adopts the 

 theory that the evaporation of water in contact with air is a process 

 identical with chemical solution, and adduces as evidence supporting 

 his views various circumstances which are common both to evapora- 

 tion and to the solution of a salt in water. 



8. " On the nature and properties of Iodide of Potassium, and its 

 general applicability to the cure of Chronic Diseases." By James 

 Heygate, M.D., F.R.S. 



The author has been led by his experience to estimate highly the 

 medicinal properties of the iodide of potassium (which he prefers to 

 the tincture of iodine) in various diseases, and thinks that when it 

 is administered judiciously no deleterious effects are likely to arise 

 from its use. 



9. " Observations on the relation which exists between the Respi- 

 ratory Organs of Animals, and the preservation of independent Tem- 

 peratures." By George Macilwain, Esq., Consulting Surgeon to the 

 Finsbury Dispensary. Communicated by W. Lawrence, Esq., F.lt.S. 



The author expresses his dissent from the prevailing opinion that 

 the temperature maintained by animals above the surrounding me- 

 dium is proportionate to the extent of their respiration ; and adduces 

 many instances among different classes of animals in which he can 

 trace no such correspondence, and others, on the contrary, where 

 increased powers of respiration appear to diminish instead of raising 

 the animal temperature. Hence the author is disposed to regard 

 respiration as a refrigerating rather than a heating process. 



CHEMICAL SOCIETY. 

 (Continued from p. 77-) 

 April 18, 1843. — The following papers were read : — 



78. " On the Spontaneous Change of Fats," by W. Beetz *. 



79. " On certain Improvements in the Instrument, invented by 

 the late Dr. Wollaston, for ascertaining the Refracting Indices of 

 Bodies," by John Thomas Cooper, Esq. 



May 2. — The following communications were read : — 



* This and all other papers read before the Chemical Society, of which 

 abstracts do not appear in these Proceedings, will be inserted at length in 

 future Numbers of the Philosophical Magazine. 



Phil. Mag. S. 3. Vol. 23. No. 153. Nov. 1843. 2 C 



