532 Chronicles of Science. [Oct., 



a short abstract. The peculiar feature of the method is the estima- 

 tion of the amount of nitrogenous organic matter by the amount of 

 ammonia which is actually formed by distillation with carbonate of 

 soda, caustic potash, and permanganate of potash. Direct experi- 

 ments have shown that all the nitrogen in urea, gelatine, and 

 albumen are obtainable in the form of ammonia by the method of 

 treatment described ; and has disclosed, the authors say, the singular 

 feet that boiling with a caustic alkali liberates one-third the nitrogen 

 of albumen and gelatine in the form of ammonia, and that a sub- 

 sequent boiling with permanganate of potash liberates the other 

 two-thirds. Thus the nitrogen of urea is obtainable as ammonia 

 by boiling with carbonate of soda ; and that of albumen by the 

 caustic alkali and permanganate. We have therefore the means of 

 distinguishing between ammonia froni the two sources. The method 

 pursued is briefly as follows : Free ammonia is first estimated in 

 the water by Nessler's test, as described by Dr. Miller. A litre is 

 then distilled with a little carbonate of soda. In this distillate will 

 be found the ammonia from urea. The distillation is interrupted 

 when ammonia ceases to pass, and caustic potash being added to the 

 contents of the retort the distillation is again proceeded with. In 

 the distillate now collected there will be ammonia representing one- 

 third the nitrogen in the albumenoid matters in the water. The dis- 

 tillation is again interrupted and crystals of permanganate of potash 

 are added, enough to give a deep violet tint, and once more the dis- 

 tillation is continued, now almost to dryness. This final distillate 

 will give the remaining nitrogen in the form of ammonia. We must 

 add that all the estimations of ammonia in the various distillates 

 are made with Nessler's test-liquor. For quantitative examples 

 of the method we must refer our readers to the original paper, 

 published in the ' Journal of the Chemical Society ' for September. 



6. ENGINEEKING— CIVIL AND MECHANICAL. 



We have, this quarter, to chronicle a more than usual extension 

 of open lines of railway, some of which, too, are of the first im- 

 portance. 



In August last, two new Welsh railways were opened. The one 

 from Aberystwith to Carmarthen, which, by completing a link in 

 the western chain of railways running through the principality, 

 opens the new route between the manufacturing districts of South 

 Lancashire and the mineral districts of South Wales. The other — 

 the Cambrian Eailway — affords an unbroken route between Aberyst- 

 with and Carnarvon. 



In India, the extension of the East India Eailway from Allaha- 



