Chemistry and Physics. 299 



required for toxical purposes. — J. Chem. Soc, lxiii, 884, 886, 

 June, IS 93. g. f. b. 



6. On the Density of Carbon monoxide and the Atomic 31ass 

 of Carbon. — The density of carbon monoxide has been carefully 

 determined by Leduc. It was prepared by the action of sul- 

 phuric acid on oxalic acid and was purified by means of potassium 

 hydroxide and dried over phosphoric oxide. Three mass deter- 

 minations of a given volume of the gas at 0° and 760 mm gave 

 the values 2*8470, 2-8478, 2*8469 ; the mean being 2-8469. Since 

 the mass of air contained in the same vessel was 2*9440 grams, the 

 relative density of the carbon monoxide is 0*96702 ; agreeing 

 with the value ordinarily accepted. If at 0°, this gas has the 

 same molecular volume as oxygen, the atomic mass of carbon cal- 

 culated from the above density is 1L*913 (O = 15*88). This value 

 agrees very closely with the numbers 11*915 and 11*917, obtained 

 by synthesis by Van der Plaat and Friedel respectively. Assum- 

 ing the experimental results to be correct, the ratio of the molecu- 

 lar volume of carbon monoxide to that of oxygen is 1*0001. It 

 has been shown that the corresponding ratio for hydrogen and 

 oxygen is about 1*002. If Regnault's value for oxygen (1*10563) 

 be assumed as true, the atomic mass of carbon would be 11*897, 

 which is not in sufficientl} 7 close agreement with the actual de- 

 terminations. There can be little doubt therefore that the 

 author's value 1*1050, is more correct. Since the relative density 

 of methane calculated from its molecular mass is 0*55376, which 

 is lower than the value generally accepted, it is probable that the 

 determinations were made with a gas not quite pure. — C. Ii., cxv, 

 1072; J. Chem. Soc, Ixiv, 165, April, 1893. g. f. b. 



7. On the Volatilization of Silica. — Although pure silica is 

 sometimes observed in the higher portions of blast-furnaces as a 

 sublimate, no direct experiments have ever been made apparently 

 to test its volatility directly. This has now been done by 

 Cramer, who used pure crystallized native silica for this purpose. 

 A Deville furnace, 12 cm in diameter and 33 cm high was heated by 

 means of graphitic carbon, a blast of air being forced in from be- 

 low. After two hours the heat obtained was equal to the highest 

 ever noticed in furnaces, platinum not only being melted but actu- 

 ally beginning to boil and evaporate. A weighed quantity of the 

 crystallized quartz was introduced into a graphitic crucible pro- 

 vided with a lid. This was put inside a second crucible of magnesite, 

 the space between them being filled with powdered magnesia. The 

 whole was now placed in the furnace, a strong blast was applied 

 and after 4 kilograms of graphite had been burned the experi- 

 ment was stopped and the quartz re-weighed. It was found to 

 have lost 40*5 per cent. After repeating the operation three 

 times the author succeeded in volatilizing the quartz completely. 

 Xo volatilization however takes place when .the temperature is 

 not above that of melting iron. — Zeit. angew. Chem., 1892, 484; 

 J. Chem. Soc, lxiii, 164, June, 1893. g. f. b. 



