204 PROCEEDINGS OF THE AMERICAN ACADEMY 



bromine, and state that xylol behaves with chlorine like toluol. A 

 paper by Limpricht* in the same volume of the Annalen <hr C/iemie 

 und Pharmacie, and another by Cannizzaro f in the next volume but 

 one, did not advance the subject materially. 



Lauth and Grimaux { in 18G7, described a convenient form of the 

 process for making benzylchloride, consisting in passing chlorine into 

 toluol heated to 110°-140°in a flask with a return-cooler. In the 

 Bame year, Beilstein § extended his law to the action of bromine on 

 toluol, which, if iodine was present, gave bromtoluol as the only pro- 

 duct with the exception of a little of some iodine compound, even if 

 the toluol was boiling, while without iodine bromine formed with boil- 

 ing toluol benzylbromide, always, however, mixed with some brom- 

 toluol. Lauth and Grimaux, || on the other hand, could find no 

 bromtoluol in the product obtained by mixing the vapors of bromine 

 and toluol. 



Since that time, but little progress has been made in this subject, 

 the papers in which the action of halogens on toluol is mentioned, 

 dealing rather with the products than with the conditions of the action, 

 but the following papers deserve mention : Fittig,^[ on the formation 

 of bromtoluol free from benzylbromide ; Beilstein and Kuhlberg,** 

 extending Beilstein's Law to the action of chlorine on the various 

 chlorine compounds of toluol, and one of their later papersft ( on tetra- 

 chlortoluol) in which they direct that 2 or 3 grs. of iodine should be 

 used to make the chlorine enter the ring. This is the only statement 

 of the amount of iodine needed for this purpose that we have been 

 able to find, and even here nothing is said of the amount of toluol to 

 be used with the 3 grs. of iodine. 



We have not been more successful in finding definite statements 

 about the temperature at which the bromine begins to enter the side- 

 chain, those authorstt who mention any temperature, give the boiling- 

 point of the substance to be acted on, or a temperature somewhat 

 above this, with the exception of Wachendorff, §§ who in studying the 

 action of bromine on para- and metanitrotoluol, found that the benzyl- 



* Ann. Cliem. Pliarm., cxxxix. S03. || Bull. Chem. Soc, vii. 108. 

 t Ibid., cxli. 198. t Ann. Chem. Pliarm., cxlvii. 39. 



t Ibid., cxliii. 79. ** Ibid., cxlvi. 317 ; also cxlvii. 339. 



§ Ibid., cxliii. 369. tt Ibid., cl. 286. 



It Vofrt and llenninjier, Ann. Chim. Phys., ser. 4, xxvii. 130. Grimaux, 

 Comptos Rendus, lxx. 1863. Kadziszcwski, Ber. d. ch. G , 1873, p. 492. 

 §§ Ann. Cliem. Pliarm., clxxxv. 259. 



