194 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



Bunsen element is passed, for three or four days, through 

 officinal solution of terchloride of antimony, with a resistance 

 of about eight hundred feet of copper wire in the circuit. He 

 has recently also detected occluded hydrogen in it, possessing 

 identical reducing properties with the hydrogen absorbed 

 by palladium. Thus, if the platinum wires, covered with re- 

 cently deposited explosive antimony, are placed in a very di- 

 lute aqueous solution of ferricyanide of potassium, the par- 

 tial conversion of the latter into f errocyanide will be evident in 

 the course often or fifteen minutes. Pure antimony, perfectly 

 free from arsenic, will not produce such a result. Since the 

 liquid employed is a hydrochloric-acid solution, the liberation 

 of gaseous hydrogen at the negative pole, with the antimony, 

 by decomposition of the acid, might be expected, but not the 

 slightest trace of it could be detected, while, on the other 

 hand, the presence of chlorine at the negative pole, in com- 

 bination with antimony, without the evolution of hydrogen, 

 is so remarkable that it seems desirable to test other metallic 

 chlorides thus electrolytically. 15 C, XXII., ISYS, 337. 



AMERICAN BROMINE. 



The increased demand for bromine, after the introduction 

 of potassic bromide into medicine in 1866, led to its prep- 

 aration from the mother liquor at the different salt-works 

 of Pennsylvania, and subsequently at those of Ohio and 

 West Virginia. The method employed is the usual one 

 with binoxide of manganese and sulphuric acid. From 

 1867 to 1870 the production increased from 11,000 pounds to 

 194,000 pounds. Up to 1870 all was consumed in the Unit- 

 ed States, but since then it has been exported. The price, 

 however, has been so depressed by excessive production 

 that no new works for its preparation are being established. 

 18 C.February 9, 1876, 95. 



DETERMINATION OF OZONE IN THE AIR. 



The determination of the quantity of ozone in the air has 

 not yet been achieved by any convenient method, since the 

 tint of the ordinary ozone test-papers is determined by the 

 velocity of the wind. It was supposed by Von Pettenkofer 

 that the absence of the ozone reaction in the atmosphere of 

 closed dwelling-rooms was due to the slight circulation in 



