M. Karnmerer on Fluorine. 213 



on cooling, a sulphur is produced which remains for a long time 

 elastic, and which, when poured on a glass or porcelain plate, is 

 obtained in flexible sheets. The same change is produced by- 

 iodide of potassium, or by even a smaller proportion of iodine. 

 The sulphur thus prepared is insoluble in bisulphide of carbon. 



The action of 1 per cent, of bromine at a temperature of 200° 

 is similar ; but the sulphur, instead of being black and having a 

 metallic lustre, has the colour of yellow wax, and is much softer 

 than the foregoing variety : about 75 to 80 per cent, are insoluble 

 in bisulphide. 



Chlorine passed over sulphur at 240° changes it into a kind 

 of soft sulphur, which can be readily drawn out and the parts 

 stuck together. It contains a rather larger proportion of sul- 

 phur soluble in bisulphide than that treated by bromine. After 

 having been worked up for an hour or two it suddenly hardens, 

 and then becomes quite insoluble in bisulphide of carbon. 



M. Karnmerer* has made the following observations on the 

 isolation of fluorine. In a perfectly dry tube, iodine w T as intro- 

 duced along with a small tube closed with a stopper and filled 

 with fluoride of silver in excess. The tube was sealed after 

 expelling all air by the vapour of iodine, and then, having 

 broken the small tube in the interior, the apparatus was heated 

 to 70° or 80°. At the expiration of twenty-four hours all the 

 iodine had disappeared, the tube was perfectly transparent, and 

 its contents colourless. The tube was opened under mercury, 

 and the gas transferred to a eudiometer, in which it was rapidly 

 absorbed by a fragment of potash. After absorbing the gas, no 

 trace of silica or iodine could be found in the liquid. The oxygen 

 displaced by the fluorine had combined with potash or water, to 

 form peroxide either of potassium or hydrogen. The tube was 

 not at all attacked. The author believes he has isolated fluo- 

 rine, and he mentions Davy's statement that fluorine does not 

 attack glass, and could be transferred over mercury. He pro- 

 poses to repeat the experiment with bromine. 



Atarignacf has communicated the abstract of a long series of 

 researches on the tungstates, fluotungstates, and silicotungstates. 

 He agrees with ScheiblerJ in considering that there are only two 

 varieties of tungstic acid — one insoluble, forming ordinary tung- 

 states precipitable by acids, and the other soluble, forming soluble 

 metatungstates not precipitable by acids. 



The constitution of the metatungstates is simple, and agrees 

 with the formula MO 4AY0 +<rAq. The neutral tungstates are 



* Journal fur praktische Chemie, vol. lxxxv. p. 452. Repertoire de 

 Chirnie, January 1863. 

 f Com pies Jiendus, December 15, 1862. X Phil. Mag. vol. xx. p. 3/4. 



