46 INSECTICIDES AND FUNGICIDES. 



sweetening substance that appears to be molasses mixed with glucose 

 sirup. Sample 20492 is evidently composed of phosphorus, corn 

 meal, and glucose sirup, and sample 20493 appears to be composed of 

 the same substances, with perhaps a little molasses. 



TOBACCO EXTRACTS. 



Only four samples of this class of goods were examined, using the 

 following methods of analysis: 



METHODS OF ANALYSIS AND DISCUSSION. 



Nicotine. 01 About 5 to 6 grams of the tobacco extract is weighed 

 out in a small beaker. Ten cc of an alcoholic soda solution (contain- 

 ing 6 grams of sodium hydroxid, 40 cc of water, and 60 cc of 90 per 

 cent alcohol) is added, followed by enough chemically pure powdered 

 calcium carbonate to form a moist but nonlumpy mass. This is trans- 

 ferred to a Soxhlet extractor and extracted for about 5 hours with 

 ether. The ether is evaporated off at a low temperature by being 

 held over the steam bath, and the residue is taken up with 50 cc of a 

 soda solution (containing 4 grams of sodium hydroxid in 1,000 cc of 

 water). This is transferred by means of water to a Kjeldahl flask, 

 capable of holding about 500 cc, and distilled in a current of steam, 

 using a condenser through which water is flowing freely. A three- 

 bend outflow tube is used and a few pieces of pumice and a small 

 piece of paraffin are added to the Kjeldahl flask to prevent bumping 

 and frothing. The distillation is continued till all the nicotine has 

 passed over. The amount of distillate varies from 300 to 500 cc, 

 according to the amount of nicotine present. When the distillation 

 is complete only about 15 cc of liquid should remain in the distilling 

 flask. The distillate is titrated with standard sulphuric acid, using 

 phenacetolin as indicator. One molecule of sulphuric acid is equal to 

 two molecules of nicotine. 



Camphor. The camphor in sample 2 I & W is determined in the 

 following manner: Weigh out about 30 grams of the sample in a small 

 beaker, add a large quantity of water to precipitate the camphor, filter 

 and wash with cold water, spread the filter paper out on a flat surface 

 and transfer the precipitate to thick dry filter paper by means of a 

 thin spatula, and press between its folds. It is again transferred and 

 pressed between filter paper. This is continued till it is dry. Trans- 

 fer to a weighed watch glass and weigh again to obtain the weight of 

 camphor. A correction is made based on the amount of camphor that 

 is dissolved by a volume of water equal to that of the filtrate above. 

 By this method low and only approximate results are obtained, but it 

 is the best method we can find to work on mixtures of this description. 



a Wiley's Principles and Practice of Agricultural Analyses, Vol. Ill, p. 605. 



