536 MM. Svanberg and Struve on the Atomic Weight 



microscope detected in the mother-liquor a salt which sepa- 

 rated in white, minute rhombohedrons. 



Experiment I. — 2*1188 grms. neutral molybdate of potash 

 furnished on treatment with sulphuretted hydrogen 29 167 

 grms., in which were contained 1*081 grm. sulphuret of mo- 

 lybdenum. 



Experiment 11. — 1*11505 grm. neutral salt furnished 1*582 

 grm. sulphurets. 



Consequently 100 parts of the neutral molybdate of potash 

 furnish — 



I. II. 



Sulphurets .... 137*658 136753 



in which is contained, according to experiment I., 51019 per 

 cent, sulphuret of molybdenum, Mo S' 2 . 



Experiment with Trimolybdate of Potash. 



Sulphuretted hydrogen does not act upon the trimolybdate 

 of potash in the cold, but if the apparatus is warmed, water 

 is instantly disengaged and sulphur absorbed. The same 

 phaenomena occur as in the preceding experiment; after sul- 

 phuretted hydrogen had been passed for ten hours over the 

 salt, and two successive weighings exhibited but a slight 

 variation, we looked upon the experiment as terminated, espe- 

 cially as in this case the glass was very much acted upon by 

 the partially fused mass. In this case we also treated the mass 

 with water and estimated the sulphuret of molybdenum. 



2*5117 grms. trimolybdate of potash furnished 3030 sul- 

 phurets, which contained 2*1656 grms. sulphuret of molyb- 

 denum. 



100 parts of the trimolybdate consequently furnish 120*635 

 sulphurets, in which are contained 86221 parts MoS 2 . 



The quantitative results which we have obtained in these 

 three experiments it is difficult to explain and to connect with 

 any theory. This is not merely owing to the bulb of the 

 reduction-tube being so acted upon by the partially fused 

 mass that the values are thereby rendered uncertain, but 

 rather to the phaenomena of decomposition being more com- 

 plicated, so that to obtain a complete explanation it would be 

 requisite to have likewise a quantitative determination of the 

 sulphosalts and metallic sulphurets extracted by the water. 

 However, as this would lead us far from the special object of 

 this investigation, we did not make this quantitative exa- 

 mination, especially as we must then have entered upon new 

 questions, for instance, what pha?nomena take place, and 

 what combinations are formed in the treatment of potash or 

 carbonate of potash with sulphuretted hydrogen at a high tern- 



