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LXXYIII. Further Remarks on Parabenzule, and on the Isomers 

 of Turpentine. By Arthur H. Church, F.C.S.^ 



SULPHOBENZOLATE of ammonium, C'^^ H^ NH^ 2S0^ 

 when submitted to dry distillation, yields (among other pro- 

 ducts which I have not examined) sulphate of ammonium, sul- 

 phobenzole, sulphophenylamide, and benzoic. The proportion 

 of benzole thus obtained is very considerable : one experiment, 

 in which 200 grammes of sulphobenzolate of ammonium were 

 distilled, yielded nearly 60 grammes of benzole. The hydro- 

 carbon thus regenerated contains sulphurous acid and other im- 

 purities, from which it may be freed by agitatiou with a strong 

 solution of hydrate of potassium. The benzole thus purified has 

 the exact boiling-point t (80°'8) of the original hydrocarbon used 

 in the pre]iaration of the sulphobenzolic acid; in evei-y respect 

 also it is precisely identical with pure benzole. 



Sulphoparabenzolic acid, which is produced when parabenzole, 

 a hydrocarbon occurring in coal-naphtha, is treated with fuming 

 sulphuric acid, yields a series of salts which, although isomei'ic 

 with those of sulphobenzolic acid, differ from them considerably 

 in })hysical properties. I have ah'eady described J the hydro- 

 carbon itself (it boils at 97°"5), the sulphoparabenzolic acid, and 

 several of its salts. I have now submitted pure sulphoparaben- 

 zolate of ammonium to distillation with the following i-esults. 

 The salt under the influence of a high temperature behaves ex- 

 actly like the sulphobenzolate ; it fuses, evolving water and a 

 white vapour, which rapidly condenses to a yellow solid in the 

 neck of the retort. Afterwards a colourless liquid comes over, 

 which, purified by hydrate of potassium and by metallic sodium 

 and then redistilled, was found to be pure parahemoXe, boiling 

 at 97°*5. Not only was its boiling-point thus separated from 

 that of benzole by an interval of 16°'7, but its odour was unmis- 

 takeably different; and it withstood a cold of —20° without the 

 least symptom of crystallization. The amount of material at my 

 disposal was too small to allow me the means of learning whether 

 the other products of this decomposition are distinct from those 

 obtained by distilling the ordinary sulphobenzolate of ammonium. 

 The regeneration of parabenzole just described may be regarded 

 as a fresh proof of the essential difference between the sulpho- 

 derivativcs of benzole and those of parabenzole, while it shows 

 that the difference between the hydrocarbons themselves is more 

 profound than is generally the case with similar isomers. Take 

 for instance the hydrocarbons isomeric with ordinary turi)entine. 

 This liquid boils at 1G0°; terebenc, a really distinct modification 



* Communicated by the Author. 



t Phil. Mag. [4] i.\. 256. + ll)id. xiii. 415. 



