416 NICOTINE 



Arffentane, or German Silver, consists of 8 parts of copper, 2 parts of nickel, and 

 3 parts of zinc. This composition has often a yellow tinge, and it is consequently 

 employed for inferior articles only. Another formula gives copper SO'OOO, zinc 25'0, 

 and nickel 25-0. 



White Argentane, or Argentine Plate, is usually copper 8 parts, nickel 3 parts, zinc 

 3 parts. This is a very fine alloy, and passes under different names, according to the 

 caprice of the manufacturer. A manufacturer's receipt which we have seen is : copper 

 60-0, zinc 17'0, nickel 23-5. 



Electrum, copper 8 parts, nickel 4 parts, and zinc 3 parts. This composition has 

 many advantages, especially in its fine colour, and its resistance of oxidation. 



Copper 8 parts, nickel 6 parts, and zinc 3 parts, is a very hard and fine compound- 

 metal ; but from its hardness there is some difficulty in working it. 



Tutenague of China Packfong of the East Indies is copper 8 parts, nickel 3 parts, 

 and zinc 3J parts. 



A solder for German silver is prepared by fusing together 4 parts of the ordinary 

 argentine and 5 parts of zinc. 



Nickel may, it appears, be alloyed with iron. Stromeyer describes a native com- 

 pound of this kind ; and Berthier states that, by heating the arsenide of nickel with 

 iron in any proportions, double arsenides are obtained, which are hard and brittle, 

 with a cast-iron colour. 



The process of nickel-plating, now extensively practised, is described under 

 ELECTBO-METALLTJBGY. 



NICOTIANA TABACUM. The tobacco plant ; so called in honour of 

 John Nicot of Nismes, ambassador from the King of France to Portugal, who 

 procured the first seeds from a Dutchman, who obtained them from Florida. See 

 TOBACCO. 



NICOTI.A.NINE. This is a concrete volatile oil, obtained by distilling tobacco- 

 leaves with water ; a turbid liquid comes over, and, after standing some time, this 

 oil forms on the surface ; only a very small quantity is produced, 6 Ibs. of the leaves 

 yield only 11 grains. This oil is solid, has the odour of tobacco, and a bitter taste. 

 It is volatile, insoluble in water and the dilute acids, and in alcohol and ether, but 

 soluble in caustic potash. It has a resemblance to camphor, and was called by 

 Gmelin ' Tobacco Camphor. 1 



NICOTINE. This alkaloid is the active principle of the tobacco-plant ; it was 

 first obtained, in an impure state, by Vauquelin in 1809. It is contained in the 

 different species of tobacco, probably in the state of malate or citrate. It was ob- 

 tained pure by Possel and Eeimann from the leaves of the Nicotiana tabacum, Maero- 

 phylla rustica, and M, glutincsa. Nicotine and its salts have been examined and 

 analysed by MM. Ortigasa, Barral, Melsens, and Schlosing. 



The following is the process employed by M. Schlosing for extracting the nicotine 

 from the tobacco : 



The tobacco-leaves are exhausted by boiling- water ; the extract is then evapo- 

 rated till solid, or to a syrupy consistence, and shaken with twice its volume of 

 alcohol. Two layers are formed ; the under layer is black and almost solid, and 

 contains some malate of lime, the upper layer containing all the nicotine. This 

 latter is concentrated by distillation, and again treated with alcohol to precipitate 

 certain substances. This solution is concentrated, and treated with a concentrated 

 solution of potash ; it is allowed to cool, and is then agitated with ether, which 

 dissolves all the nicotine. To the ethereal solution is added powdered oxalic acid, 

 when oxalate of nicotine is precipitated as a syrupy mass. This is washed with ether, 

 treated with potash, taken up with water, and distilled in a salt-bath, when the nico- 

 tine comes over, and may be rendered pure and colourless by redistilling in a current 

 of hydrogen. 



M. Melsens has observed the presence of nicotine in the condensed products of 

 tobacco-smoke. The oil which is formed in pipes after smoking tobacco in them, 

 and which gives the colour to the pipe, contains nicotine. The question may then 

 perhaps be asked, ' If tobacco-smoke contains such a deadly poison, why are there 

 not more ill effects from smoking ? ' It may perhaps be answered in this way : tobacco 

 when smoked only yields about ^th r less of its weight of nicotine, and then very 

 little of that is condensed in the mouth. And, again, the system may become accus- 

 tomed to it, as is the case with opium-eaters, and then it requires much more to take 

 an effect ; it can scarcely be doubted, though, that the continual habit of smoking 

 large quantities of tobacco is injurious. 



Nicotine when pure is a colourless, transparent, oily liquid, possessing an acrid 

 odour and an acrid burning taste. Its density is 1-024, and that of its vapour 5-607. 

 It restores the blue colour of reddened litmus, and renders turmeric brown. It 

 becomes yellowish by ago, and when exposed to the air becomes brown and thick, 



