Section of Chemistry and Electricity, 395 



&c. And it seems highly probable that the salts of nicotin will ad- 

 mit of useful medicinal applications. 



After the author had ascertained the principal facts already stated 

 respecting nicotin, he found that he had been anticipated ; he ob- 

 served in the ' Quarterly Journal of Science, Literature, and Art,' for 

 December 1829, that MM. Posselt andReimann had la.ely obtained 

 a vegeto-alkali from tobacco, examined its properties, and combined 

 it with a number of acids. But though those chemists are justly 

 entitled to the merit of having first made known to the public an 

 interesting series of facts respecting nicotin, the author's experiments 

 may serve to corroborate their general results, and also throw addi- 

 tional light on the subject. 



On a peculiar Fluid obtained in the manufacture of Pyroxylic Spirit. 

 By M. Scanlan. 



The author has been for some past engaged in the making of 

 pyroxylic spirit*, a fluid now extensively used in England as a sub- 

 stitute for alcohol, principally by hat manufacturers, for the purpose 

 of dissolving shell lac and mastic to stiffen their hats and render 

 them water-proof. 



In the process which Mr, Scanlan pursues, he obtains a fluid of 

 a higher specific gravity, but having a lower boiling point than py- 

 roxylic spirit, and differing from it in other respects. 



Rough pyroligneous acid is submitted to distillation in a copper 

 still, by the maker, in order to separate some of the tar it holds in 

 solution ; he sets apart the first 15 per cent, that distils over, and 

 this he sells as wood spirit. This liquor, as it comes from the py- 

 roligneous acid maker, contains much free acetic acid and tarry 

 matter. 



The author proceeds to saturate the acetic acid by means of 

 slacked lime, which causes the separation of some pitch. 



He next submits the saturated liquor to distillation as long as 

 the distilled product is of less specific gravity than water. 



This last product is rectified in a still somewhat on the plan of 

 those for a long time in use on the Continent, and now coming into 

 general use in this country, for the purpose of rectifying spirit. It 

 consists of a boiler, containing the liquor submitted to distillation, 

 and of a rectifier, which is a copper vessel of peculiar construction, 

 placed in a bath of water, which must be kept at such a temperature 

 as will condense water, but still retain the more volatile products in 

 the state of vapour till they pass into the last part of the apparatus, 

 where they are condensed and finally cooled. 



In this process of rectifying, the author was a good deal sur- 



* It is known by the name of naphtha by those who deal in and con- 

 sume it. [This fluid was discovered in 1812 by Mr. Philip Taylor, who 

 published an account of its properties, giving it the name of pyroligneous 

 gather, in 1822. See Phil. Mag., first series, vol. lx. p. 315. In the fol- 

 lowing year it was examined by MM. Macaire and Marcet, by whom it was 

 termed pyroxylic spirit. See Bibliotheque Universelle for October, 1823 ; 

 and also a paper by MM. Dumas and Peligot, Annates de Chimie el de Phy- 

 sique, tome lviii. p. 70, or our present number, p. 427. — Edit.] 



3E2 



