56 



JOURNAL OF THE 



1.0700 gram'5. of pubstanoe vielded .1321 rrams. of AgCe or 12.34 per ct. 

 CI and .8440 grams Ba ^O, or 19 62 perct CNS 

 calc. found 



Pbo 68 46 68 57 68.55 



CI2 1191 12 34 



(0^S)2 19.41 - 19.63 



The formula for the compound then is PbCl^. Pb(CNSX. 

 There is no water of crystalHzation and the substance can be 

 he.ited to 150° without decomposition. 



The solution poured off from the original lead chlor- 

 sulpho-cyanide yielded mainly crystals of potassium chloride, 

 together with some unchanged potassium sulpho-cyanide. 

 The potassium sulpho-cyanide used was freshly prepared 

 and purified by frequent recrystallization. 



It is proposed to pursue farther the study of these double 

 compounds of lead in the laboratory here. 

 Chem. Laboratory, U. N. C. 



SOLUBILITY OF ALUMIN'A. IN SULPHURIC ACID. 



R G GRTSSOM. 



Ordinary commercial alumina is not very easily acted on 

 by sulphuric acid, and this solubility varies very decidedly 

 with the strength of the acid. The following experiments 

 were undertaken to determine at what concentration the acid 

 has the most powerful solvent action. 



The sulphuric acid used contained 95.25 per ct. H, SO,. 

 Ten grams of alumina were put in a 200 c. c. flask, and the 

 mixture of sulphuric acid and water (cold) poured upon it. 

 A series of such flasks were heated to 30° for one hour. The 

 contents were then largely diluted and filtered as rapidly as 

 possible into looo c. c. flasks. The alumina was then deter- 

 mined in duplicate, using 25 c. c. for each determination. 



