Mixter — Formation of Trisodium Orthoj)hosphate, etc. 107 



heating it out of contact with air as long as water came off. It 

 was free from a higher oxide. 



The experimental data are as follows : 



6 7 8 



ADtimony trioxide 9*985 gr. 10-318 gr. 8*994 gr. 



Sulphur 2-000 " 1-800 " 2-200 " 



Sodium peroxide 28 "25 " 28 " 



Water equivalent of system 4,110 "4,097 " 4,182 " 



Temperature interval". 4*190° 4*008° 4-209° 



Heat observed 17,221° 16,417° 17,602° 



" of oxidation of sulphur —10,542° — 9,488 c — ll,596 c 



" " " "iron... — 48 c — 48 c — 48 c 



6,631 c 6,881 c 5,958 c 



Fori gram.. 664 c 667° 662 c 



The oxygen absorbed or evolved in each of the combustions 

 was insignificant. Different mixtures were taken in order to 

 learn whether or not the thermal result is influenced by the 

 proportions of antimony trioxide, sulphur and sodium peroxide. 

 The fact that the results are the same indicates that the same 

 sodium antimonate was formed in each instance. 



The mean of the experiments is 664 and for one gram mole- 

 cule of antimony trioxide it is 191,500 c . 



Antimony Tetroxide. 



Antimony tetroxide was made by heating antimonic acid in 

 an electric furnace until the product did not lose weight at a 

 dull red heat. In the following experiments the absorption of 

 oxygen was insignificant : 



9 10 



Antimony tetroxide 10-233 grams 7*386 grams 



Sulphur" 2*000 " 2*000 " 



Sodium peroxide 23 " 22 " 



Water equivalent of system. 4,161 " 4,180 " 



Temperature interval 3-871° 3486° 



Heat observed 16,107° 14,571° 



" of oxidation of sulphur. —10,542° —10,542° 



" " " " iron —48° —48° 



5,517° 3,981° 



For 1 gram ._ 539° 539° 



The result for 304*4 grams of antimony tetroxide is 164,100°. 



In all of- the combustions of antimony and its oxides the 



oxidation was complete and no antimonite was formed. The 



