418 Miscellaneous Intelligence, 



22. Investigation of Tobacco — Nicotia. — It has been two or three 

 times supposed that a vegeto-alkali has been obtained from tobacco, 

 to which its peculiar properties are due. Lately MM. Posselt and 

 Reimann have resumed the investigation, and think they have ob- 

 tained the true principle by two processes, i. Mix Ijlb. of 

 tobacco with 2 ounces of potash and enough water ; distil in a glass 

 retort ; add fresh water to the residue in the retort, and again distil ; 

 repeat this two or three times; after which the leaves will be found 

 deprived of their acrid property, and harmless if taken internally. 

 The united products are to be neutralized by sulphuric acid, and 

 evaporated nearly to dryness ; the irregularly crystallized brown 

 mass is to be acted upon by strong alcohol, the solution diluted 

 with a little water, and distilled. The brown aqueous residue is to 

 be treated with concentrated potash, and again distilled, when a 

 clear light-coloured oily substance will be obtained, very acrid, with 

 an odour which, though slight at common temperature, becomes 

 insupportable by elevation of temperature. Ether added to this 

 substance in successive portions takes away the acrid principle, and 

 the solution, when distilled, leaves the pure principle in a very con- 

 centrated state, ii. Or boil 121b. of dry tobacco leaves in water, 

 acidulated with sulphuric acid, evaporate, and treat the residue with 

 alcohol, diluted with a ninth of water ; add a little water to the 

 solution, and distil; add hydrate of lime to the aqueous residue, and 

 redistil ; the product being mixed and agitated with ether, the latter 

 is to be poured off, and a fresh portion added as before. All the 

 ethereal solutions are to be conjoined and put in contact with 

 muriate of lime, which will take away the water ; and the con- 

 centrated ether solution being evaporated or distilled, will leave 2 

 gros or 118 grains of reddish brown nicotia. 



Pure nicotia is limpid, and liquid at 21° F. ; its odour resembles 

 that of dry tobacco ; its taste very acrid, burning, and enduring. It 

 stains paper, but the mark disappears in some hours: it is heavier 

 than water, volatilizes in the air, and boils at 474° F. It burns 

 round a wick, and produces white vapours at 212°F. It dissolves 

 in water in all proportions, and the solution has an alkaline reaction. 

 It dissolves in alcohol; but when this solution is distilled, the nicotia 

 does not pass over. Ether dissolves it in any quantity, but neither 

 does its vapour carry any portion up. Acids take the nicotia from 

 these ethereal solutions, and form salts insoluble in ether. The phos- 

 phate of this substance is crystallizable with difficulty, forming a 

 substance having the appearance of cholesterine. The sulphate is 

 uncrystallizable ; nitric acid destroys the body in part; oxalic and 

 tartaric acids form crystallizable soluble compounds. — Geiger'sMag. 



23. Preparation of Urea, by M. Henry. — Let a slight excess of 

 the subacetate or the hydrate of lead be added to recent urine ; a pre- 

 cipitate will fall which will contain salts formed by the union of 

 the acids in the urine with oxide of lead, and also a combination of 



