412 EXPEEIMENT STATION EECOED. 



A sensitive test for the detection of phenol and salicylic acid, J. M. Wilkie 

 {Jour. ,Soc. Chem. Indus., 30 {1911), No. 7, pp. /^0,3-//(^.'/).— The test is based on 

 the formation of tri-iodo-phenol by adding iodin solution to solutions containing 

 phenol, salicylic acid, etc. 



Polarimetric determination of nicotin in tobacco juice and tobacco, J. De 

 (JRAZIA (Fachl. Mitt. Ostcrr. Tabakregir, 10 (1910), Xo. 3, pp. 81-90, figs. 2; 

 Jour. 8oc. Chcni. Indus., 30 (1911), No. H, pp. 506, 507; abs. in Chem. Abs., 5 

 (1911), No. 15, p. 2507). — The method is as follows: "Thirty gm. tobacco juice 

 are mixed with 3.5 gm. CaO and 10 cc. ILO, and distilled rapidly with a cur- 

 rent of steam until about ISO gm. distillate have been collected. The rotatory 

 power of this distillate is determined in a 200 mm. tube and the percentage 

 of nicotin calculated from the formula P=aGf/g; G is weight of distillate, g 

 that of tobacco juice, and / is a factor ('rotation constant') taken from the 

 table given. For tobacco, 20 gm. of the finely iwwdered material are treated 

 with 7 cc. KOH solution (1:1) a few grams NaCl, and 130 cc. boiling concen- 

 trated NaCl solution, and distilled first rapidly without steam until about 45 cc. 

 have come over, and then with steam until the distillate amounts to 100 cc." 



Factor / is used for the purix>se of correcting the change of rotary ix)wer 

 of the nicotin which is due to temperature. 



The determination of nicotin in concentrated tobacco juices, J. Schkodeb 

 (Chem. Ztg., 35 (1911), No. ^2, p. 382). — Results are reported in this paper of 

 4 analyses made with various methods and in different localities of the same 

 tobacco extract. Analyst No. 1, using the Schlossing method, obtained 6.41 per 

 cent of nicotin ; analyst: No. 2, using the Kissling method, 6.23 per cent ; and 

 analysts Nos. 3 and 4, 9.4 and 8.8 per cent, respectively, their methods not being 

 stated. The author announces an unpublished colorimetric method devised by 

 Kissling and expresses the hope that it will soon be available to all making 

 nicotin determinations in such extracts. 



A polemical discussion in regard to the Ulex method (E, S. R., 25, p. 211) is 

 also included. 



Accurate estimation of nicotin in tobacco and in green plants of Nico- 

 tiana tabacum, R. Mellet (Schweiz. Wchnschr. Chem. u. Pharm., 49 (1911), 

 No. 9, pp. 117-120; abs. in Chem. ZentbL, 1911, I, No. 21, p. 1561; Analyst, 36 

 (1911), No. 424, p. 31/8). — The Toth method, according to this author, is a good 

 one for estimating nicotin in solution or in tobacco extracts, but requires some 

 modification in order to apply it to solids. The following method is the one 

 the author employs : 



" Thii-ty gm. in the case of dry tobacco, and 250 gm. in the case of the 

 green plant, are treated with boiling water in a well-closed flask, and after 24 

 hours the liquid is cooled and milk of lime added. The flask is again closed 

 and allowed to stand for a further 24 hours with frequent agitation. The liber- 

 ated nicotin is distilled off in a current of steam, in such a way that the 

 volume of liquid in the flask is reduced. When the volume of distillate at- 

 tains 2 to 3 times that of the original liquid the operation is stopped and the 

 distillate is acidified with sulphuric acid. It is then evaporated to a small bulk 

 with exclusion of air, and, after the addition of potassium hydroxid, the nicotin 

 is extracted with ether. The ethereal solution, containing some ammonia, is 

 concentrated until all the latter is eliminated. The remainder of the ether is 

 evaporated at the ordinary temperature; the residue is dissolved in water and 

 titrated with tenth-normal sulphuric acid. Estimations effected with known 

 quantities of nicotin indicated that the total losses of the alkaloid amounted 

 to 0.06 gm., which figure must be added to the values found." 



Estimation of nicotin in tobacco extracts, W. Koenig (Chem. Ztg., 35 

 {1911), No. 58, pp. 521, 522; abs. in Analyst, 36 {1911), No. fy2}i, pp. 3Jt8, 349).— 



