Chemistry and Physics. 463 



I by Bartli in his article (i. e. by the action of sulphuric 

 e upon fused and pulverized benzoic acid), and tried tlie 

 ifrimtnt with the potassium salt of this acid. The only 

 ' tluit made itself evident in the result was that less para- 

 lic aeiil was present in the product than in the former 

 iii,di by no means an inconsiderable quantity. 

 ,', I subjected to the same process sulphobenzoic acid, that 

 ared by simply heating benzoic acid with weak fui 



mply 



acid, and found that also in this case a mixture results, 

 • be expected after the two previous experiments. 

 -0 acids cannot be separated by means of partial crystal- 

 If the aqueous solution was not too dilute, the first por- 

 • rystallized out contained, in the two last cases, the 

 Jt'ol" t!ie oxybenzoic acid probably mixed with a little 

 ■lii/oie acid. On evaporating the mother liquor further, 

 !;al ])arts of the two acids crystallized out. The crystals 

 be partially sorted out, and 



rated Ironi the accompanying acia. 



■i paration of the basic barium salt of 



slu's a means for an imperfect separation. 



basic barium salt of paraoxybei 



' is difficultly soluble in water, and is pre- 

 water is added to a solution of the neutral 



neans no basic salt of oxybenzoic acid is pro- 

 portion of the paraoxy benzoic acid can be 



idition. There always remains a sufficient 



I solution, however, to render the oxybenzoic 



the above experiments, that for the preparation 

 3ic acid, crude sulphobenzoic acid cannot be 

 1 be necessary to subject it to some process of 

 simplest means that presents itself for this pur- 

 ition of the acid barium salt, 

 occupied in endeavoring to isolate and learn the 

 ulphoacid, the formation of which is in all prob- 

 :"ause of the formation of paraoxybenzoic acid, 

 the most favorable conditions for'its formation, 

 carefully study certain uncommon phenomena, 

 Y be traced back to this, that the fact above dis- 

 be ])resent been overlooked. 



the i 



iro^copic Gon,hrnation; by 

 Mlliman, dated Kome, April 

 nee to you the discovery of 

 }- the aid of which one can > 

 I'.'S^aar protuberances with 

 ^amelield. 





* Zeitsohrift fur Cliemie, N. F., : 



