whole thoroughly and transfer to a Soxhlet extractor and exhaust for about 

 five hours with ether. Evaporate the ether solution at a low temperure by 

 holding over the steam bath, and take up the residue with 50 cc of the dilute 

 sodium hydroxide solution. Transfer this residue by means of water to a 

 500 cc Kjeldahl flask, and distill in a current of steam, using a condenser. 

 (Use a few pieces of pumice, and a small piece of paraffin, to prevent bump- 

 ing and frothing.) Continue the distilliation till all the nicotine has passed over 

 the distillate usually varying from 400 to 500 cc. When the distillation is com- 

 plete, only about 15 cc. of the liquid should remain in the distillation flask. 

 Titrate the distillate with standard sulphuric acid using cochnical as indicator. 

 One molecule of sulphuric acid solution is equivalent to two molecules of nico- 

 tine. This is the Official method adopted by the Official Agricultural Chemists. 



DETERMINATION OF TOTAL SULPHUR 



Take an aliquot portion of the solution representing 1 to 2 cc of the orig- 

 inal concentrated Lime-Sulphur solution, place in a 200 cc. beaker, with 25 cc. 

 of hydrogen peroxide (H2 O2 ), 2 cc of concentrated Sodium hydroxide and 

 about 25 cc of water. Then the beaker after being covered with a beaker 

 cover was placed on the water bath for two hours until all of the sulphur was 

 oxidized to calcium sulphate. After oxidation is complete, neutralize the 

 solution with hydrochloric acid, precipitate the sulphur with Barium Chloride 

 solution as Barium Sulphate. Let stand over night, filter and weigh the pre- 

 cipitate after ignition, in a platium or porcelain crucible. 



DETERMINATION OF LIME (CaO) 



Take an aliquot portion of the dilute Lime-sulphur solution and oxidize 

 the suphur in the solution with hydrogen peroxide, as in the determination of 

 Total Sulphur; make the solution acid with acetic acid, then alkaline with am- 

 monium hydroxide and precipitate the calcium as calcium oxalate. Filter the 

 solution while hot, wash precipitate thoroughly and place the filter paper con- 

 taining the precipitate in hot water containing about 5 cc of concentrated sul- 

 phuric acid. Titrate the solution with a standard Potassium purmanganate so- 

 lution in the usual manner. 



The determination of Total Arsenic and water soluble arsenic was deter- 

 mined by the methods outlined in the Bulletin No. 107 (revised) of the Official 

 Agricultural Chemists, Department of Agriculture, Bureau of Chemistry, so- 

 lution used in the experiment:- 



1. Concentrated Lime-sulphur solution. 



Specific Gravity = 1 . 1 750 or 2 1 Baume'. 

 Per cent Total Sulphur = 12.86 

 Per cent Total Lime (CaO) =6.43 

 Per cent Calcium (Ca.)=-4.59 



2. Nicotine solution called Black Leaf 40, Nicotine sulphate or Nico-sul. 



Specific Gravity of solution at 15 C.= 1.2120. 



Per cent of Nicotine in the solution ^40.50 



Per cent of combined Nicotine (as sulphate) 13.12 



Acidity expressed as H2 SO4 ~12. 13 percent. 



Came the same using Phonolthalein or Cochineal as Indicator. 



