502 



it may fairly be concluded that the rationale of each is the same, and 

 that they differ only in the amount of action. 



February 15, 1844-. 

 SIR J. W. LUBBOCK, Bart., V.P., in the Chair. 



" Some further Observations and Experiments illustrative of the 

 Cause of the Ascent and continued Motion of the Sap," in continua- 

 tion of a Paper presented to the Royal Society in November 184'2. 

 By G. Rainey, Esq. Communicated by P. M. Roget, M.D., Sec. R.S. 



The author here gives an account of some experiments which he 

 has lately made, tending, in his opinion, to corroborate the opinions 

 he advanced in his former paper; namely, that the ascending sap is 

 situated in the intercellular and intervascular spaces of the plant, and 

 that its passage into the cells is effected by the action of endosmose, 

 which the intervening membranes, whether living, or deprived of 

 vitality, exert upon that fluid. He found that portions of many plants, 

 such as Anthriscus vulgaris^ and the Lapsana communis^ absorb a 

 much larger quantity of fluid when they are immersed in pure 

 water, than when similarly immersed in a solution of gum-arabic ; 

 and that, in the latter case, the remaining portion of the solution is 

 of the same specific gravity as before any part has been absorbed by 

 the plant. By a similar process, the author conceives, the fluid Avhich 

 is derived from the earth, and has passed into the intercellular spaces 

 of the cotyledons, are imbibed by its cells by endosmose ; while at 

 the same time a fluid containing sugar is passing, by exosmose, out 

 of these cells into the intercellular and intervascular tissue, and thence 

 into the corresponding tissue of the peduncle and young stem ; it 

 there meets with, and is diluted by the water ascending in the same 

 tissue from the roots, and the mixture is afterwards distributed over 

 every part of the plant. 



February 22, 184-4-. 



SIR J. W. LUBBOCK, Bart., V.P., in the Chair. 



^' On the Temperature of the Springs, Wells and Rivers of India 

 and Egypt, and of the Sea and Table Lands within the Tropics ; 

 with a few Remarks on M. Boussingault's mode of ascertaining the 

 mean temperature of Equinoctial Regions." By Lieut. Newbold, of 

 the Madras Army, F.R.S. 



The author adverts to the deficiency of information .which has 

 hitherto existed as to the temperature and chemical composition of 

 the springs and rivers both of India and of Egypt ; and also as to 

 their geographical and geological relations. He gives, in the present 

 paper, the details of a great number of observations which he has 

 made on these subjects, and which he thinks may prove a useful con- 

 tribution to Indian hydrography, as well as afford more exact data 

 for philosophical inquiry. The observations extend, at irregular in- 



