94 ll£POKT— 1»88. 



of a salt crystallising without water, and the dimorphism, and consequent 

 sapersaturation, lends support to the view that supersaturation is due to 

 the fact that the individual in solution differs from that which crystallises 

 out. 



Soluhility of salts in aqueous solutions of alcohol. 



That salts are less soluble in alcohol than in water has been shown 

 by the experiments of Schiff and Girardin, but hitherto the attempts to 

 trace out the connection between the solubility and the amount of alcohol 

 present have entirely failed. 



A series of experiments on this subject has been commenced and 

 considerable progress has been made towards completion. The method of 

 experiment is as follows : Solutions of alcohol of definite strengths are pi*e- 

 pared by diluting absolute alcohol with weighed quantities of water. The 

 composition of the solutions thus obtained is checked by a comparison of 

 their densities with the table given by Mendeleef ; 10 to 15 cc. of these 

 solutions, which are of definite molecular strength (5, 10, 15, &c., mole- 

 cules of alcohol to lOOHgO), are placed with excess of salt in the saturation 

 appai'atus referred to above, and after 24 hoars, during which time the 

 contents of the tubes have been shaken 20,000 times, the clear solution is 

 poured off, evaporated to dryness, and weighed. 



The salts suitable for these experiments are few in number. No 

 hydrated salts can be used and the anhydrous salts must be freely 

 soluble in water, otherwise their solubility in dilute alcohol sinks so low 

 that the experimental error becomes too high. 



Up to the present only four salts have been examined, NaCl, KCl, 

 K'aNOg, and KNO3, in four solutions of alcohol up to 20 molecules, but 

 the densities of solutions of these salts in the alcohol solutions have also 

 been determined. The results have yet to be worked out. 



The Committee propose to complete the experiments in these two 

 branches of the subject and then turn their attention to the vapour- 

 f)ressures of water from solutions, the special apparatus for which has 

 been long ready. With this view they desire to be appointed for another 

 year. 



Report of the Committee, consisting of Professor Eay Lankester 

 Mr. P. L. ScLATER, Professor INI. Foster, Mr. A. Sedgwick, 

 Mr. Walter Heape, Professor A. C. Haddon, Professor Moseley, 

 and Mr. Percy Sladen {Secretary), appointed for the purpose 

 of maJcing arrangements for assisting the Marine Biological 

 Association Laboratory at Plymouth. 



Your Committee have the pleasure to report that on June 30 last the 

 laboratory and tanks of the Marine Biological Association at Plymouth 

 were formally declared open and ready for work. 



Immediately afterwards Mr. Cunningham, Mr. Weldon, and Mr. 

 Bourne, assisted by Mr. Garstang, secretary to the Director, began to 

 explore methodically that part of Plymouth Sound lying within the 

 breakwater. The results of the exploration are not j-et ready for publi- 



