104 Mr Christie on Magnetic Influence in the Solar Rays. 



to ascertain if there be any foundation for the vulgar opinion 

 of the continual growth of the diamond. Dr Brewster's opi- 

 nion is rather in favour of it than otherwise. It is certain 

 that in these hot climates crystallization goes on with wonder- 

 ful rapidity, and I hope at some future period to produce un- 

 deniable proofs of the recrystallization of amethyst, zeolite, 

 and felspar in alluvial soil. 



Observations by the Editor. 

 Science has sustained a great loss by the death of Mr Voy- 

 sey since the preceding paper was printed. He was geologist 

 to the trigonometrical survey in India, under the late Lieuten- 

 ant Colonel Lambton, and thus enjoyed the best opportunities 

 of studying the geology and mineralogy of that interesting re- 

 gion. The undeniable proofs which, at the end of the above 

 paper, he promises to produce, respecting the recrystallization 

 of amethyst, zeolite, and felspar, in alluvial soils, will, we 

 trust, be published by those who shall obtain possession of his 

 papers. The information which Mr Voysey has given respect- 

 ing the matrix of the diamond, is very important in reference 

 to any theory of its origin ; but we do not see that it, in any 

 way, affects the probability of the conjecture which we had 

 hazarded, and which Mr Voysey quotes at the beginning of 

 his paper. 



Art. XIII. — On Magnetic Influence in the Solar Rays. By 

 S. H. Christie, Esq. A. M. F. R. S. of Trinity College, 

 Cambridge, Fellow of the Cambridge Philosophical So- 

 ciety, and of the Royal Military Academy. In a Letter to 

 the Editor. 



Dear Sir, 

 In the accompanying paper, which I think may be in- 

 teresting to you,* I have given an account of some ex- 



* We intended to have laid before our readers an abstract of Mr Chris- 

 tie's very able paper ; but the following letter, in addition to the new ex- 

 periments which it describes, contains such a succinct and perspicuous sum- 

 mary of the principal results in the original memoir, that it supersedes the 

 abstract which we had proposed to give. This new discovery of Mr Chris- 

 tie's must be regarded as one of very great value, and will no doubt lead to 



