560 



" On some peculiar modifications of the Force of Cohesion, with 

 reference to the forms and structure of Clouds, Films and Mem- 

 branes." By William Addison, Esq., F.L.S. Communicated by P. 

 M. Roget, M.D., Sec.R.S. 



In the course of his researches into the nature and origin of tu- 

 bercles in the lungs, and into the physical properties of the secre- 

 tions of the human structure, the author had occasion to notice va- 

 rious fibrous and membranous forms arising solely from physical 

 agencies. On pursuing the inquiry, he observed a class of pheno- 

 mena indicating some peculiar modifications of the force of cohesion. 

 Thus he found that transparent liquid streams are visible when va- 

 pours or fluids mingle with one another, and also when solids are 

 dissolving in a fluid ; and that opake deposits, assuming the appear- 

 ance of clouds, form on those streams, rendering visible the lines 

 of junction of two fluid or gaseous surfaces. A great number of 

 experiments are described- illustrating these general facts, which are 

 afterwards applied to explain various phenomena of clouds, films 

 and membranous formations, resulting from the operation of the 

 different cohesive forces which are called into action, under a diver- 

 sity of circumstances, when liquid or gaseous bodies are brought 

 into mutual contact. 



" On the formation or secretion of Alkaline and Earthy Bodies 

 by Animals." By Robert Rigg, JEsq., F.R.S. 



From the results of a comparison made by the author, of the 

 weight of the ashes obtained from a quantity of bread, equal to that 

 which was the sole food of two mice during thirty-eight days, with 

 the weight of the ashes of their excretions during the same period, 

 it appeared that the latter exceeded the former in the proportion of 

 1334 to 934. The amount of soluble salts was also found to be 

 greater in the latter than in the former. From these data, the 

 author infers that both alkaline and earthy bodies are formed out 

 of their elements by the animal system, and found in their excre- 

 tions. 



" An Account of the Observation of the total Eclipse of the Sun 

 on the 21st of December 1843." By Lieutenant J. O. E. Ludlow, 

 E.I.C. Engineers, Superintendent of the Magnetic Observatory at 

 Madras. Communicated by J. C. Melville, Esq., F.R.S., Secretary 

 to the Hon. the Court of Directors of the East India Company. 



The author reports the results of his observation of the eclipse, 

 which was unfortunately much interrupted by the passage of clouds : 

 and he has also taken the opportunity of making observations on the 

 Magnetic Dip and Horizontal Intensity at certain places on his 

 journey. 



" On the Barometrical Variation as affected by the Moon's De- 

 clination." By Luke Howard, Esq., F.R.S. 



In this paper, which is a continuation of that which was published 

 in the Society's Transactions for 1841 (p. 277), and in which the 



