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LIV. Letter from J. Hume, Esq. on the Formation of 

 Nitrous Ether, by Means of Nitrate of Menxury, and on 

 other Discoveries supposed to be modern. 



DEAR SIR, To Mr. Tilloch. 



P RO.\r reading a paper which appeared in a lite number of 

 the Philosophical Magazine, I am induced to conclude 

 that the process for obtaining nitrous ether, by means of 

 nitrate of mertury and alcohol, published above forty years 

 ago, is not so generally known as it deserves ; it is, there- 

 fore, but fair, in order to do justice to its author, to take 

 the most effectual method to assert the priority, by referring 

 to the work itself; and that I may more certainly gain your 

 concurrence to give an early insertion to this communiQa" 

 tion, I shall be as brief as possible. 



I know not the exact period when the work to which X 

 allude was published, as there is no date affixed j but as 

 the author speaks of several of his contemporaries, particu" 

 larly of the celebrated anatomist Cheseldeh, it must have 

 been written at least forty years ago — ^^the title is " Mis' 

 cellanea verc utilia." 



From some particular expressions of the author I am 

 inclined to believe that, without his being aware of it, he 

 was in possession of the fulminating mercury *, for his at- 

 tention seems to have been chiefly absorbed in the forma- 

 tion of the ether, or, as he terms it " a spirit prodigiously 

 volatile," and, consequently was not so much, if at all, 

 applied to investigate the powder or " milky " appearance 

 in the mixed fluiclSj which has Since been proved to be the 

 most important, or rather wonderful, part of the produce. 



I suspect, were we industrious enough to search for 

 them, that many of what arc stated to be the modern dis- 

 coveries were well known to, and probably described by, 

 our ancestors. An instance of this, amongst others, has 

 lately occurred to me, viz. a chemical lamp, in all respects 

 similar to Argand's, but with tuo concentric wicks ; the 

 invention of this is said to be of very modem date, and is 

 ascribed to Webster. 1 have now in my possession a lamp 

 of this description, made more than twelve years ago, for 

 it was then bought by an eminent brass-founder in Hart- 

 street, Covent-garden, as old metal. From its magni- 

 tude it must have been employed in a light-house. It has 

 two coii'cntric wicks attached to a single rack, which are 



Vol. XVII. No. 68. U moved 



