Chemistry and Physics. 319 



heat is developed, and hence it is really the determinant of the re- 

 action. From the same causes, a boiling concentrated solution of 

 potassium cyanide attacks platinum, setting free hydrogen ; an ex- 

 periment the authors recommend as a convenient one to illustrate 

 the principles of thermo-chemistry upon the lecture-table. So also 

 a boiling solution of mercuric cyanide does not attack platinum 

 unless potassium cyanide be present ; then the mercury at once 

 separates. — (J, B., Ixxxii, 241, Jan. 1876. g. f. b, 



3. On a New Compound of Sulphur and Oxygen. — For many 

 years it has been known that the action of sulphur on sulphuric 

 oxide or on disulphuric acid produces an intense blue color. R. 

 Weber has successfully investigated the cause of this color, and 

 has shown that it is due to a new oxide of sulphur which he has 

 isolated. To prepare it, a portion of sulphuric oxide is prepared, 

 containing some sulphuric acid, and into this is thrown, in small 

 portions, carefully dried flowers of sulphur. At the instant of con- 

 tact the sulphur is converted into dark blue liquid drops which 

 sink to the bottom of the liquid and there soHdify. Care should 

 be taken to keep the temperature at 15° C, since below this point 

 the whole liquid solidifies, and above it the blue body decomposes. 

 After the operation, the excess of liquid is poured off, the blue crys- 

 talline crusts are drained and the excess of sulphuric oxide driven 

 off at a temperature not exceeding blood heat. Bluish green crusts 

 are thus obtained, which are very friable and which have a structure 

 similar to malachite. They decompose without fusion slowly at 

 ordinary temperatures, more rapidly on heating, evolving sulphur- 

 ous oxide and leaving sulphur behind. In a cool place the decom- 

 position is so slow^ that the substance niay readily be weighed for 

 analysis. Moist air decomposes it rapidly and it hisses when thrown 

 into water. Alcohol and ether also decompose it, and set free sul- 

 phur. A mean of five closely accordant analyses showed that it 

 contained 5M2 per cent of sulphur; thus giving it the formula 

 ^gOg. The author names it sulphui 



4. On the Purification of Carbon disulphide.—F rif^ubbug pro- 

 poses to effect the final purification of carbon disulphide by treating 

 jt with fuming nitric acid. The crude disulphide is first purified 

 py repeated distillation with a vegetable fat, such as palm oil, and 

 18 then treated with the acid and frequently agitated. After twenty- 

 tour hours two layers are observed, nearly of the same color, the 

 red vapors of the acid having been absorbed by the CSg. If water 

 J'e added, the disulphide becomes reddish violet, and this separated 

 irom the acid, washed, and gently heated, gives up pure disulphide 

 m the distillate, while the violet-colored solution of the disulphide 

 remains behind, and is not broken up except at a higher tempera- 

 t iY*^i • ^^^^ colorless distillate, washed with water dried and dis- 

 tilled, is chemically pure. The author is investigating the solvent 



