INDUSTRIAL PROGRESS DURING THE YEAR 1875. lxxv 



Schrotter has proved that when the spark passes through 

 a Geissler tube containing phosphorus vapor, the walls of the 

 tube are covered with a thin layer of amorphous phosphorus. 

 Moreover, if the vapor is contained between two sealed 

 tubes, and the spark passes through the interior one, the 

 same effect results, showing that it is due to induction. 



Terquem and Trannin have described a new and conveni- 

 ent form of apparatus for piercing glass by the electric spark. 



Pickering and Strange have given the results of their 

 measurements on one of Farmer's large dynamo-electric ma- 

 chines. With a speed of 1280 revolutions per minute, a light 

 of from 650 to 900 candle-powers was obtained. 



A large Gramme magneto-electric machine was received 

 from Paris in February by the University of Pennsylvania, 

 at Philadelphia, which gives very remarkable results when 

 used for producing the electric light. 



Champion, Pellet, and Grenier have published a memoir 

 upon the applications of electricity to the firing of blasts, of 

 torpedoes, and to mining purposes generally, in which are 

 considered the recent improvements in electromotors, in 

 primers, and in fuses, with the various methods of using 

 them to the best effect. * 



CHEMISTRY. 



General Chemistry. Some advance has been made in 

 chemical theory. Michaelis and Wagner have shown that 

 while two bodies having the empirical constitution of ethyl 

 sulphite are known, yet only one of these is the true sulphur- 

 ous ether, as proved by its mode of preparation. In this lat- 

 ter compound the ethyl groups are both united to the thionyl 

 by oxygen, and hence the sulphur in the radical must be a 

 tetrad. Zimmermann has made a similar research on ethyl 

 phosphite, and comes to the conclusion that phosphorous 

 acid is a trihydroxyl derivative of phosphorus, and that in 

 the ether neither of the ethyl groups is directly united to 

 the phosphorus, since in that case ethyl -phosphinic acid 

 w T ould appear as a decomposition product. From this the- 

 oretical position the author proceeded to prepare tri-sodium 

 phosphite, which he obtained only as a thick sirup, but in 

 which the ratio of the phosphorus and the sodium could be 

 determined. 



