220 EDWARD DIVERS AXD TAMEMASA HAGA; 



Name of the acid. — Berglund accepted sulphamic acid, then in use, 

 as an alternative name for the acid he had discovered, but employed 

 that of amidosulphonic acid. This name, the use of which is now general, 

 is analogically incorrect, and needs to be changed into either aminc- 

 sulphonic acid or amidosulphuric acid. Similarly, imidosul phonic acid 

 and nitrilosulphonic acid should be altered to amine-disulphonic and 

 amine-trisulphonic acids, or to imidosulphuric and nitrilosnlphuric 

 acids. But it seems of little moment to make the chance, so lon^ as 

 ethylsulphonic acid remains in use in place of ethanesulphonic acid, 

 and ethylsulphuric acid is misapplied to ethyl hydrogen sulphate. 

 Sulphamic acid must remain in the back ground, until such time as 

 sulphimic acid becomes acceptable for imidosulphuric acid, and some 

 analogous name has suggested itself as suitable for nitrilosulphuric 

 acid. 



Formation of the acid. 



1. Sulphur trioxide and ammonia, according to Berglund, 

 sometimes yield a very little ammonium amidosulphonate along with 

 the imidosul phonate, the chief product, when the ammonia is kept in 

 large excess. He gives no details of his method of testing for it, and 

 before he has stated that he has occasionally found it in very small 

 quantity, he guardedly says that it probably can be formed in this 

 way. The difficulty presents itself that even at 135° ammonium 

 amidosulphonate begins to change into imido.sulphonate, while the 

 temperature caused by the union of sulphur trioxide and ammonia is 

 much higher than that, and Berglund mentions that he did nothing to 

 keep down the temperature. But, although the amidosulphonate does 

 begin to change at so low a temperature as 135°, a little of it can 

 remain unchanged at temperatures not very far below 300° (see the 

 latter part of this paper). So that on the whole, when it is considered 



