184 
IOWA ACADEMY OF SCIENCE 
The slightly low values shown for chlorine are due probably 
to the presence of some acid in the acid chloride. In all its 
reactions this form of the chloride seems more labile than the 
symmetrical form, and while the decomposition is very slow 
by water or heat, yet it seems to take place to a definite degree. 
It will be noted that the values for nitrogen or sulphur would 
be almost unaffected by the transformation of a small amount 
of the acid chloride into the acid, what little difference might 
be produced being according to the indications of the analysis. 
Some Other Attempts to Make the Acid Chlorides. 
Since the use of phosphorous pentachloride is attended by 
the production of the fumes of phosphorous oxychloride, and 
also as the yield of the acid chlorides made by that method is 
not as large as might be desired, an attempt was made to use 
sulphuryl chloride for their preparation. An attempt was made 
on the potassium salt of the 6-nitro-3-methyl-4:-sulphobenzoic 
acid, which forms the chloride more easily than the acid which 
we were investigating. Four grams of the material were mixed 
with about 3 grams of the SO 2 CI 2 , and the mixture heated with 
the use of a refiux condenser for several hours. On pouring 
into water, it solidified at once, but when an attempt was made 
to crystallize from carbon tetrachloride it refused to dissolve, 
showing that the acid chloride, which is easily soluble, had not 
been formed. The product slowly dissolved in water. The acid 
chloride apparently could not be formed in this way. 
Since chlorsulphonic acid has a higher boiling point than the 
sulphuryl chloride, an attempt was made to use it as in the 
preceding case. Pour grams of the potassium salt of the 6- 
nitro-3-methyl-4-sulphobenzoic acid were treated with the cal- 
culated amount of chlorsulphonic acid, and heated with the use 
of a refiux condenser. The material melted and gases were 
given off, the action apparently being vigorous. On pouring 
into water and filtering the residue, only a very small amount 
of the acid chloride seemed to have been formed. 
Another attempt was made by using twice the theoretical 
amount of the chlorsulphonic acid, heating on the steam bath, 
and dropping more carefully into cold water so as to prevent 
hydrolysis. The oily precipitate solidified and settled over night. 
When this was filtered and washed, the yield was about twenty- 
five per cent of that demanded by the theory. On recrystalliz- 
