2 1 8 Roi/al Socich/. 



and diminished by the affinity exerted on them by the molecules of 

 the water; whilst if some of these molecules of water are neutralized 

 by mixture with another soluble principle, they cease to act as an 

 obstacle to the crystallization of the body, which then takes forms 

 more complicated and approaching nearer to that of the normal solid 

 with a curved surface. 



M. Necker considers that the new views he has sketched require, 

 for their complete developement, many ulterior details, as well as 

 many new experiments and new facts ; but that the tendency which 

 the crystals of all systems present, to progress towards the curved 

 surface form appropriate to each system, by the complication of their 

 forces, is a fundamental fact of the first importance ; and that an ad- 

 vance has been made by showing the bearing of the important ex- 

 periments of MM. Leblanc and Beudant, and by having brought 

 the theory of crystallography nearer to those views which the pro- 

 gress of chemistry and of physics have led us to adopt, relative to 

 the form of the elementary molecules of bodies. 



January 24. — A paper was read, entitled, "Experiments made 

 on a piece of Peiia silver, saved from the Lady Charlotte, wrecked 

 on the coast of Ireland in December 1 838, as to its capabiUty of 

 holding water." By W. D. Haggard, Esq. Communicated by Sir 

 Henry Ellis, K.H., F.R.S. 



Plata Peiia, so called, is silver collected by quicksilver after the 

 ore is pounded ; it is then placed in a mould, and by great force the 

 quicksilver is squeezed out, when it forms a mass, resembling dry 

 mortar, of great porosity. 



Troy Weight. Decrease 



lbs. oz. dwts. in weight. 



Originalweightwhen taken from the 1 gg ^^ ^ ibs oz dwts 



box J 



One day placed before the fire 37 15 19 5 



Third day 35 5 17 



Fifth day 34 5 5 1115 



Eighth day 34 2 5 3 



Weight of water 4 9 3 



Increase 

 Weight Of the piece supposed to be -I 3^ ^ 3 ite" oz.^dwk 



qmte dry J 



First dav from the fire 34 3 1 



Tliirdday 34 2 5 2 2 



Fifth day 34 4 2 1 17 



Eighth day 34 4 9 7 



Gained in water from the air 4* 7 



Weight after water had been forced 1 ^g ^ jg 4 9 10 



into it J 



Total weight of water contained in the piece 5 1 17 



A paper was also read, entitled, " On the Application of the Con- 

 version of Chlorates and Nitrates into Chlorides, and of Chlorides 

 into Nitrates, to the determination of several equivalent numbers." 

 By Frederick Penny, Esq. Communicated by H. Hennell, Esq. 

 F.R.S. 



