214 E - DIVERS AND T. HAGA 



crystals to be anhydrous, and Fremy's analysis and formula agree 

 with this Unding. But it is now known that Fremy's analytical 

 results cannot be relied on, and we have already had to give an 

 instance of this in the present paper and shall have to give others. 

 Differing from Claus, we find all the crystals of this salt to effloresce 

 slowly over sulphuric acid, and to give on analysis results indicating 

 the presence of one molecule of water. Solutions show a great ten- 

 dency to supersaturate, and it becomes often quite difficult to crys- 

 tallise them. When thoroughly dry the crystals can be kept for 

 months without undergoing much change, but moist they are 

 unstable, hydrolysing and becoming acid to litmus. The acidity 

 developed is that of hydroxyammonium sulphate, hardly showing 

 with methyl-orange. Heated they suddenly intumesce below 100° 

 and thoroughly decompose. 



To determine the sulphur and nitrogen we hydrolysed the salt 

 in a sealed tube with hydrochloric acid at 130° C, here following 

 Easchig's process, which gives, however, somewhat irregular results 

 as we afterwards found (see the analysis of the dibarium salt). The 

 hydroxyamine thus [»reduced was measured by iodine after addition 

 of potassium acid-carbonate. Water could not be removed by ex- 

 posure over sulphuric acid at the ordinary temperature and pressure 

 rapidly enough to be convenient for analytical purposes, this and 

 other sulphazotised salts retaining, according to our experience, part 

 of their crystallisation-water with great tenacity. Nor coidd the 

 water be well expelled in the oven, because of the decomposition of 

 the salt at about 95°. But we made a fairly good estimation of it, by 

 moderately heating the salt in a Sprengel-pump vacuum, in a long 

 bulbed tube containing also sulphuric acid. The following is a table 

 of our results— 



