296 CARNEGIE INSTITUTION OF WASHINGTON. 



This conclusion was based largely upon the results obtained by 

 treating the two compounds with dry ammonia in solution in anhy- 

 drous ether. One of them gives the ammonium salt of orthocyan- 



benzene-sulphonic acid, C6H4<^ o^ rkATxr > and the other gives the 



\c5U2UiMi4 /CO\ 



ammonium salt of benzoic sulphinide, C6H4'('^^ y'N.NH4. It 



seemed to me probable that the chloride which gives the ammonium 

 salt of orthocyan-benzene-sulphonic acid is the one having the unsym- 

 metrical formula, and that the one that gives the other product has 

 the symmetrical formula. The connection is indicated thus: 



I ^''^'\^of}^ ^ ^«^Ks020NH4 



II CeH4<^^^^i — > CeH4<^^>.NH4. 



Other reactions gave conflicting results, though those with aniline 

 were fairly consistent and, so far as they went, these seemed to me to 

 justify the conclusion drawn. In several cases both chlorides give the 

 same product and sometimes these are symmetrical and sometimes 

 unsvmmetrical. With phenol, for example, both give sulphonphtha- 



C(C6H40H)2 



lein, C6H4<^ >0 , which is unsymmetrical, while with benzene 



both give symmetrical products, either the diphenyl compound, 

 C6H4<(' Mp. p" TT^, or the sulphon-chloride, C6H4<(' ^^ J, ^. 



Later Dr. C. A. Rouiller, who was then my assistant, made the 

 important observation that the high-melting chloride is transformed 

 quantitatively into the low-melting when heated to 40° with aluminium 

 chloride. This accounts for the fact that both chlorides give the same 

 product when treated with benzene and aluminium chloride, for the 

 temperature necessary to bring about reaction in this case is above 

 that at which the transformation takes place. This raised the ques- 

 tion whether different products might not be obtained from the two 

 chlorides by using toluene instead of benzene, as toluene is more sus- 

 ceptible to the action of reagents than benzene. Further, it was thought 

 that the temperature at which the reaction takes place might be lowered 

 by working under diminished pressure, as was first suggested by Verley.^ 



The experiments with toluene were first carried out by Dr. M. B. 

 Hopkins working with me. It was found that the high-melting 



C(C6H4. 0113)2 

 chloride gives a product to which the formula C6H4\' > 



\S02 



must be assigned; while the low-melting chloride gives a sulphinic 



iBull. soc. chim. [3], 17, 20G. 



