74 



Scientific Intelligence. 



utes are required for the reduction. The metal contains from 8*6 

 to 1285 per cent of carbon; but if placed in fragments in a 

 carbon crucible brasqued with chromium oxide and again sub- 

 jected to the arc, the metal is obtained quite free from carbon. 

 If chromite be thus treated an alloy of chromium is obtained. If 

 the mixture of oxides obtained by calcining uranium nitrate be 

 mixed with a slight excess of carbon, strongly compressed in a 

 crucible of carbon, imbedded in magnesia, and submitted to the 

 arc produced by a current of 450 amperes at 60 volts, reduction 

 takes place at once, an ingot of 200 to 220 grams being obtained 

 i*t 12 minutes. The metal is very hard, has a brilliant fracture, 

 and contains from 5 to 13 - o per cent of carbon. Although its 

 fusing point is higher than that of platinum, it decomposes water 

 at the ordinary temperature. — C. Ii., cxvi, 347, 349, 549, Feb., 

 March, 1893. G. f. b. 



4. On. the Production of Sarcolactic acid by the Fermentation 

 of Inactive Lactic acid. — Having obtained a bacterial growth 

 possessing the power of exciting an active fermentation in solu- 

 tions of calcium lactate, Frankiand and MacGregor have 

 studied the resulting products. They find that by the inter- 

 rupted bacterial formation of ordinary inactive calcium lactate 

 a liquid' may be obtained which shows a negative rotation in the 

 polarimeter. From this liquid they have extracted the residual 

 lactic acid and by converting it into the zinc salt have obtained 

 by fractional crystallization a laevorotatory zinc lactate proved by 

 its chemical composition and its specific rotation to be pure zinc 

 sarcolactate. By converting this into the calcium salt, it was 

 found to possess the same specific rotation as calcium lactate. If 

 the fermentation was interrupted too early a large quantity of the 

 inactive acid remained mixed with the active one; while if too 

 long continued, the active lactate was destroyed. — J. Chem. Soc, 

 lxiii, 1028, Aug. 1893. g. f. b. 



5. On the Seats of Combustion of Gaseous Hydrocarbons. — 

 Carefully purified gaseous hydrocarbons have been burned by 

 Berthelot and Matignon in a calorimetrical bomb by means of 

 compressed oxygen and their heats of combustion in this way 

 determined. Preliminary experiments made with hydrogen gave 

 68*15 large calories at constant volume and 6899 large calories at 

 constant pressure ; the values obtained for carbon monoxide being 

 67*9 and 68*2 respectively. This gives +26*1 for the heat of 

 formation of this latter substance. For the hydrocarbons, the 

 values obtained were as follows : — 



Heat of combustion \ M ,.' 



( Const, press. 



Heat of formation 



Heat of combustion \ „ ' 



I Const, press 



Heat of formation +30 5 



Methane. 



Acetylene. 



Ethylene. 



Ethane* 







340-05 



370-9 



213-5 



315-7 



341-1 



372-3 



+ 18-7 



+ 58-1 



— 14-6 



+ 23.3 



Propane, 



Allylene. 



Propylene. 



Trimethy- 

 lene. 



526-7 



472-4 



497-9 



505-6 



528-4 



473-6 



4993 



507-0 



+ 305 



-52-6 



-9-4 



-17-1 



