258 



Mr. A. H. Church on the Benzole Series. — 



Benzole. Toluole. 



85°-5 

 Faraday. 



86° 



Mitscherlich. 



80°-4 

 Kopp. 



80°-5 

 Mansfield. 



80°-8 

 Church. 



Xylole. 



Cumole. 



144° 

 151°-4 



Gerliardt 



and 

 Caliours. 



148° 

 F. Abel. 



148°-4 

 Church. 



Cymole. 



171° 

 Mansfield. 



171°5 



Noad. 



175° 

 Gerhardt. 



170°-7 

 Church. 



114° 129 c 



Gerliardt. Caliours. 



113° 126°-2 



Mansfield. Church. 



108° 

 Deville, 

 Pelletier, 



and 

 Walter. 



109°-5 

 Noad. 



110° 



Wilson. 



106° 



Glenard 



and 

 Boudault. 



103°- 7 

 Church. 



My own results are, I believe, strictly comparable with one 

 another, having been obtained by the employment of the same 

 apparatus in similar circumstances. The differences in the 

 results of other observers may arise from very many causes, and 

 in most cases no particular accuracy was aimed at. Kopp found 

 that with benzole from benzoic acid (not purified by distillation 

 from potassium, &c), the temperature indicated by a thermo- 

 meter with the bulb immersed in the vapour, differed from that 

 indicated when the bulb was in the liquid by 0°-9 C. ; with per- 

 fectly pure benzole, and if care be taken to adopt all the precau- 

 tions I have mentioned, the difference is greatly diminished. 



After obtaining the results which have been given in the pre- 

 sent communication, I examined some of the distinguishing 

 reactions of the bodies operated upon, in order to satisfy myself 

 of their identity with those described under their respective names. 

 As the boiling-point of toluole observed by me differed so con- 

 siderably from those observations previously announced, I made 

 analyses of the purified toluole employed in my experiments. 

 These were perfectly satisfactory, as were also determinations of the 



sulphatcof barytain sulphotoluolatcof baryta, C 14 < gQ 2 >BaS0 4 j 



