468 SOLANACE^. 



does not concrete even ut - 10° C. It has a strongly alkaline reaction 

 an unpleasant odour, and a burning taste. It quickly assumes a brown 

 colour on exposure to air and light; and appears even to undergo an 

 alteration by repeated distillation in an atmosphere deprived of 

 oxygen. Nicotine dissolves in water, but separates on addition of 

 caustic potash ; it occurs in the dried leaves to the extent of about G 

 per cent., but is subject to great variation. The seeds of tobacco arc 

 stated by Kosutany^ as grown in Hungary to contain from 0-28 to 067 

 per cent, of the alkaloid. 



It has not been met with in tobacco-smoke by Yohl and Eulenberg 

 (1871), though other chemists assert its occurrence. The vapours were 

 found by the former to contain numerous basic substances of the 

 l)icolmic series, and ceded to caustic potash, hydrocyanic acid,^ sul- 

 phuretted hydrogen, several volatile fatty acids, phenol and creasote. 

 ihere was further observed in the imperfect combustion of tobacco tlie 

 formation of laminae fusible at 94° C, and having a compositiou C"H'^ 

 Oxide of carbon is also largely met with. 



Tobacco leaves, whether fresh or dried, yield when distilled with 

 water a turbid distillate in which, as observed by Hermbstadt in 1823, 

 there are formed, after some days, crystals of Nicotianin or ToUcm 

 tamjphor. According to J. A. Barral, nicotianin contains 712 per cent. 

 ot nitrogen (?). By submitting 4 kilogrammes of good tobacco of the 

 previous year to distillation with much water, we obtained nicotianin, 

 Hoating on the surface of the distillate, in the form of minute acicular 

 ciystals, which we found to be devoid of action on polarized light. 

 1 he crystals have no peculiar taste, at least in the small quantity we 

 tried ;^ they have a tobacco-like smell, perhaps simply due to the water 

 adliermg to them. When an attempt was made to separate them by ^ 

 iiiter,_they entirely disappeared, being probably dissolved by an accom- 

 panying trace of essential oil. The clear water showed an alkaline 

 leaction partly due to nicotine; this was proved by adding a solution 



>i tannic nr-iil «r^^i^^^ ^ i _ n , ^, . ,.,•;. t.t? i- „-,^ ,'o 



71 ^';^«;™■ ^n smoking, these substances, as well as the cellulose 

 ot tne thick midrib, would yield products not agreeable to the con- 

 sumer ihe manufacturer therefore discards the midrib, and endea- 

 vours by lurther preparation to ensure at least the partial destruction 

 01 these unwelcome constituents, as well as the formation of certain 

 products of fermentation (ferment-oils), which may perhaps contribute 

 to the aroma of tobacco, especially when saccharine substances, liquorice, 

 or alcohol, are added in the maceration to which tobacco is subjected^ 



iobacco leaves are remarkably rich in inorganic constituents, the 

 proportion_ varying from 16 to 27 per cent. Accmding to BoussingJt'It- 

 tliey contain when dry about 1 per cent, of phosnhorfc acid, and fiom 

 mrflv ^-"^f ''^; ^f potash, together with 2^ to 4| per cent, of nitrogen 



flo ni^.l''-. ' ^""T ^^ "^^^-^t^' «^ that to enable the tobacco plant io 

 nouush, ,t must have a rich soil or continual manuring.* 



^teM^5;^,/«^'''«-^^"--/'<. 1874. 98. 



the chemis 

 Bonssiiig'i"" 



^ Pogo;iale ai 1 \{ . I ^.IZ"'' ^^'^- ■^^- ^ For further particulars on ui. :- 



