106 General Monthly Meeting. [April 4, 



soil, the air, the weather during that growth ; and its general similarity 

 to other plants of its kind, to the organic laws that controul the con- 

 ditions of its species ; so must the crystal be considered as the result 

 of many co-operating influences, including those of the foreign consti- 

 tuents of the mother liquid, those of temperature and other physical 

 conditions, and involving the principle that the molecules, whether 

 those deposited, or those about to become so, affect and are affected by 

 — and that to considerable distances — the whole of the formed and 

 forming crystal matter. 



It would be as useless to expect to explain the growth of a crystal 

 without some such view as this, as to endeavour to account for the 

 growth or outward form of a particular plant by the development of 

 a single leaf. 



In closing the remarks made in this discourse.upon the theoretical 

 bearings of crystallo-physical and especially optical investigation, on 

 our views of the structure and constitution of crystals, the speaker 

 could only allude to the important practical services they have already 

 rendered to mineralogy, especially in the able hands of M. Descloi- 

 seaux in Paris, who has been enabled to determine several mineralogical 

 species by their means. 



[N. S.-M.] 



GENERAL MONTHLY MEETING, 



Monday, April 4, 1859. 



William Pole, Esq., M.A. F.R.S. Treasurer and Vice-President, 



in the Chair. 



Sir Thomas Fowell Buxton, Bart. 

 John Stuart Glennie, Esq. 

 Herbert William Hart, Esq. 

 James Hopgood, Esq. 

 John Henry Le Marchant, Esq. 

 Arthur Giles Puller, Esq. 

 Charles Ratcliffe, Esq. F.S.A. F.L.S. 

 William Salmon, Esq. 



were duly elected Members of the Royal Institution. 



Thomas B. Baskett, Esq. and 

 Hall Rokeby Price, Esq. 



were admitted Members of the Royal Institution. 



