470 Scientific Intelligence. [Dec. 



* # * I am not aware that any process for covering metals with 

 platinum has been hitherto published, but have little doubt, from 

 some trials that 1 have made, that the process followed for gild- 

 ing by means of the amalgam of gold would answer likewise with 

 platinum. A great deal depends upon the affinity of the metal 

 for mercuiy. Of course it will be more difficult to succeed on 

 steel than on copper. On brass the process should be easy. 

 The surface of the brass should be in the first place amalgamated 

 frith mercury, and much will depend upon the state of the amal- 

 gam. If ray correspondent would take the trouble to visit some 

 of the gilding manufactories at Birmingham, for example, he 

 would probably meet with a solution of most of his difficulties. 

 In some cases, the method of M. Leithner, described in the 

 Annals of Philosophy, v. 20, might, perhaps, be practised with 

 advantage. — T. 



IV. On the Alloy of Platinum and Tin. By Dr. Clarke. 



(To Dr. Thomson.) 

 DEAR SIR, 

 In the number of your Annals for September last (vol. xiv. 

 No. iii. p. 229), there is a communication from me upon the sub- 

 ject of an experiment alluded to by one of your former corres- 

 pondents. It is that which relates to the astonishing affinity of 

 platinum and tin at no very exalted temperature before the common 

 blow-pipe. By some unaccountable mistake, the word lead has 

 been substituted for that of tin. By reference to the notice of 

 your correspondent Mr. Fox, (p. 467, vol. xiii.)you will perceive 

 thai it never was my intention to describe any other effect than 

 that produced by the fusion of platinum and tin. Throughout 

 the whole of my late communication, therefore, for lead and 

 lead-foil read tin and tin-foil. The effect of melting platinum 

 and lead together is well known ; the two metals unite tranquilly 

 together ; but when tin is substituted for lead, the effect takes 

 place which I have described ; and the light and heat emitted 

 are truly surprising. E. D. Clarke. 



V. Chemical Chair at Berlin. 



The chemical chair at Berlin, left vacant by the death of 

 Prof. Klaproth, is still unoccupied, Prof. Berzelius and Prof. 

 Gmelin, of Heidelberg, having declined filling it. A young man 

 of some talents, who is to follow Berzelius to Stockholm, and 

 to study for some years under his auspices, is spoken of as des- 

 tined to become Professor of Chemistry. 



VI. Water of the Dead Sea. 



The water of the Dead Sea has attracted the attention of 

 chemists in consequence of the great quantity of salt which it 

 contains. A very elaborate aad, I believe, accurate analysis of 

 \t was published a good many years ago by Dr. Marcet in the 



