Ixxii GENERAL SUMMARY OF SCIENTIFIC AND 



Weber has discovered a new compound of sulphur and oxygen, 

 which has the formula S^O^, and which he calls sulphur sesquioxide 

 or dithionic oxide. It is prepared by acting on sulphuric oxide, 

 containing a trace of sulphuric acid, with sulphur. A dark blue 

 compound separates in liquid drops, falls to the bottom, and solidi- 

 fies in crystalline crusts. Below 15 Centigrade it is sufiiciently per- 

 manent to be weighed. Selenium forms a similar compound, con- 

 taining both oxygen and sulphur. 



Behrend has described a new method of preparing sulphuryl 

 chloride, which consists in heating sulphuric chlorhydrin in sealed 

 tubes to 170-180 for ten to fourteen hours. The yield is satis- 

 factory. 



Scheurer-Kestner has examined the gas which is produced by the 

 combustion of pyrite, in reply to Bode. The sulphurous oxide va- 

 ries from 6 to 9 per cent., the oxygen from 6 to 9 per cent,, and the 

 nitrogen from 84 to 85.5 per cent. 



Olivier has given an elaborate paper descriptive of the sodium 

 nitrate regions of South America, illustrated with an excellent map 

 of the region. 



Friedburg has proposed the use of fuming nitric acid for remov- 

 ing the last traces of impurity from carbon disulphide. The two 

 are distilled together ; the distillate is washed and rectified. 



Nilson has made an elaborate investigation of the arsenic sul- 

 phides, by which he has thrown much light on the modes of forma- 

 tion and the reactions of these bodies. 



Champion and Pellet have investigated the conditions of the de- 

 composition of nitrogen iodide and chloride. Since both chlorine 

 and bromine disjDlace iodine from its combinations, it is natural to 

 infer that these bodies will decompose nitrogen iodide. It is de- 

 composed with explosion when placed at the end of a tube in which 

 chlorine is being evolved, or in the vicinity of a rod moistened with 

 bromine. The temperature at which the iodide detonates is 48 Cen- 

 tigrade. Notwithstanding Abel's opinion of its inconstant compo- 

 sition, the authors believe it to be uniform when made by placing one 

 gramme iodine in 10 c. c. ammonia, agitating, allowing to stand ten 

 minutes, filtering off, washing twice with 10 c. c. ammonia, and then 

 with water. It is placed on gelatin paper, and covered with gold- 

 beater's skin gummed down while still moist. On drying, the skin 

 contracts and holds it fast. As to the chloride, the authors attrib- 

 ute its explosion in contact with turpentine to the attraction which 

 this oil has for chlorine, and the ease with which it gives up its 

 hydrogen. This view is strengthened by the fact that, when satu- 

 rated with chlorine, the turpentine does not explode the chloride. 



Acworth has examined the action of nitric acid upon copper, 

 mercury, silver, etc., with a view to determine the gaseous products. 

 He finds (a) that copper acted on by cold dilute nitric acid evolves 



