808 EXPERIMENT STATION RECORD. 



pered 200 cc. flask to a temperature of 0° C. Five ce. of hundredth-normal 

 iodiu solution are then added, the mixture is shaken, again cooled in ice water, 

 100 cc. of petroleum spirit cooled to 1° C. are added, the contents of the flask 

 are shaken for 1 minute, cooled in ice water, and the excess of iodin is then 

 estimated by titrating 50 cc. of the petroleum spirit with hundredth-normal 

 thiosulphate solution, starch solution being added as an indicator toward the 

 end of the titration. The amount of iodin which has combined with the starch 

 in the grains may then be calculated, and from this the quantity of starch 

 present is obtained, 1 cc. of hundredth-normal iodin solution corresponding 

 with 0.025 gm. of starch. 



" The author finds that brewers' grains of A'arious origin contain fx'om 0.90 

 to 4.8 per cent of starch." 



Notes on investigations on some South African tobaccos, M. Lundie (So. 

 African Jour. Set., 8 (1912), Wo. 6, pp. 186-191). — After discussing the culti- 

 vation of tobacco in South Africa, the author gives the results of analyzing 

 some African tobaccos, as follows: Virginia leaf (Hester), flue-cured Rhodesian 

 grown, 2.14 per cent nicotin and 12.15 per cent ash; Turkish tobacco (Rhode- 

 sian grown), 2.52 per cent nicotin and 10.25 per cent ash; Pondo tobacco 

 (Elliotdale district, Pondoland), 1.45 per cent nicotin and 14.58 per cent ash; 

 Kafir tobacco (Willowvale district, Transkei), 1.13 per cent nicotin and 14.26 

 per cent ash; Karoo tobacco (Oudtshoorn), 4.92 per cent nicotin and 19.16 

 per cent ash; and Cango tobacco (Oudtshoorn), 1.44 per cent nicotin and 12.02 

 per cent ash. 



The following method was used in the investigation : " The tobacco leaves 

 are first dried at a temperature of between 60 and 70°, or in a desiccator, to 

 remove all moisture. The ribs are then removed and the leaves crushed in a 

 mortar to a fine powder. Twenty gm. of this fine tobacco powder are weighed 

 out in a porcelain dish, 10 cc. of the sodic hydrate solution added (6 gm. of 

 solid sodic hydrate dissolved in 40 cc. of water and filled up to 100 cc. with 

 alcohol of 96 per cent volume), and the contents of the dish mixed, trans- 

 ferred to a Soxhlet apparatus, and the nicotin extracted by means of ether. 

 This is allowed to continue for about 2 hours, when all the nicotin contained 

 in the 20 gm. taken will be in solution in the ether. The ether is recovered by 

 attaching the flask of the Soxhlet apparatus containing the nicotin in ether to 

 a long Liebig condenser and distilling over the ether. The residue in the flask 

 will be the nicotin, chlorophyll, etc. (The ether may also be expelled by plac- 

 ing the flask in a water bath previously heated to about 50° C. and placed at 

 a safe distance from any flame. Even the hot sun suffices to drive off the 

 ether. ) 



" To the residue in the flask'add 50 cc. of sodic hydrate solution made by 

 dissolving 6.4 gm. of solid sodic hydrate in 100 cc. of water. Attach to this 

 flask a cork with a glass inlet connected to a boiler, and the outlet to a Liebig 

 condenser, and hence distill over the nicotin until the distillate measures 500 

 cc. . . . Remove 100 cc. of this by means of a pipette into a clean beaker, and 

 titrate by means of a deci-normal solution of sulphuric acid, using cochineal 

 as indicator, until violet-blue turns onion-red. . . . Repeat, using 100 cc. each 

 time, and take the average number of cubic centimeters of deci-normal sulphuric 

 acid used. Let a?=average number of cubic centimeters used for each titration. 

 Then a? X 0.0162X25= percentage of nicotin." 



A comparison is made with the tobaccos grown in the West Indies and in 

 North America. 



Qualitative reactions of the vegetable tannins, E. Stiasny and C. D. Wil- 

 kinson (Collegium, 1911, Nos. 475, pp. 318-324; 476, 325-332; ahs. in Jour. Soc. 

 CJiem. Indus., 30 (1911), No. 19, pp. 1172, 1173).— A discussion of methods. 



