METHOD. 



About ."> t< i; grams of tobacco extract or 20 grams of finely powdered tobacco, 

 [which has been previously dried at 60 C so as to allow it to be powdered, is 

 weighed out into a small beaker. Ten culm- centimeters of the alcoholic- soda 

 [solution is added, followed, in the case of the tobacco extract , with enough C. P. 

 powdered calcium carbonate to form a moist but not lumpy mass. The whole 

 [is well mixed. Tins is transferred to a Soxhlet extractor and exhausted for 

 about 5 hours with ether. The ether is evaporated off at a lo\\ temperature by 

 being held over the steam bath, and the residue is taken up with ">() ec of the 

 weak soda solution mentioned above under "solutions required." This is trans- 

 fen !! by means of water to a Kjeldahl flask, capable of holding about .">(M 

 and distilled in a current of steam, using a condenser through which water is 

 Mowing rapidly. A three-bend outflow tube i- used, and a feu pieces of pumice 

 and a .-mall piece of pa ratlin are added to prevent bumping and frothing. The 

 distillation is continued till all the nicotin has passed over, the distillate usually 

 varying from KM) to ~.<M) cc. When the distillation is complete only about 15 cc 

 of the liquid should remain in the distillation Mask. The distillate is titrated 

 with standard sulphuric acid, using pheiiacetolin or cochineal'a> indicator. ( >ne 

 molecule of sulphuric acid is equivalent to two molecules of nicotin. 





NICOTIN, METHOD II I'KMVISIONAL). 



SOLUTIONS RKljriKKP. 



A weak sodium hydroxid solution containing -1 grams to the liter :tnd a standard 

 fth-normal hydrochloric acid solution. 



METHOD. 



A solution of ('. P. nicotin of approximately 1 per cent strength is first pro- 

 pared and an aliquot portion carefully tit rated against fifth-normal hydrochloric 

 acid, using methyl orange as indicator, so as to definitely establish the exact 

 percentage <>f nicotin in solution. A separate portion of the same solution is 

 then placed in a -Ill-cm tube and its rotation in terms of the sugar scale deter- 

 mined, lly dividing the percentage of nicotin present by the reading on the 

 -II.MI -cale the value of one degree of the >cale in terms of per cent of nicotin 

 is established and the figure so obtained can be used as a factor in all determi- 

 nation- of nicotin made, provided the same polariscope is used. 



A \\eighed amount of the sample, about .'! to "> grams, is now rendered alka- 

 line with '<> cc of the weak -oda solution, mentioned under " solutions required," 

 and transferred to a round-bottomed flask of about ::m to r(K) cc capacity with 

 l.'iOec of distilled water. The whole is nou subjected to distillation in a current 

 of steam and the distillate made to a volume of fiw cc. A portion of the dis- 

 tillate is then placed in a Id-cm tube and a polariscope leading taken. Know- 

 ing the value of each degree of tin- -ii-ar -cale in terms of per cent of nicotin in 

 the solution, the per cent of nicotin in the sample can be calculated. 



FOK.MAUX. 



I OBM u.i'i.HYi'i:. Mi riion I. 

 BOL1 PIOHfl REQ1 U 



A normal solution of sulphuric acid, a normal solution of sodium hydi.. 

 and a solution of purified litmu-. 



