Proceedixgs of the Polytechnic Associatiox. 1033 



Dr. Parmelee. — This is in fact the earliest process known for mak- 

 ing iron, the process adopted bv the old Hindoos. By this process 

 a pure tine iron is obtained, but the difficulty is that your slag will 

 be so rich in iron that it will pay you to erect a blast furnace by the 

 side of your other works, for you will in foct have an ore-bed of very 

 rich ore on your premises, that ore being the slag which will contain 

 from lift}' to sixty per cent of pure iron. 



Dr. Feuchtwanger. — I have supplied the parties with large quanti- 

 ties of nitrate of soda and manganese, and they all seem to be very 

 well pleased with it. 



Dr. Parmelee. — That they turn out first rate iron, and that they 

 purcliase manganese and nitrate of soda in large quantities, I have no 

 doubt ; but I very much doubt the statement that they make it pay. 



Dr. Yanderweyde illustrated on the black-board the chemical 

 reactions which occurred. 



Dr. Parmelee. — That by these means you can get rid of all the 

 "uncombined carbon, I have no doubt, but that you can get of the 

 last portion of carbon, that which is comhined with the iron, I utterly 

 deny. I have seen it tried over and over again, without success. 



New Tin Mines. 



The great value of the tin workings at Junk, Ceylon, said to be 

 not less than 15.0,000 tons per annum, have incited a Chinese mer- 

 chant to propose the development of the tin district at the Isthmus 

 of Kra, in Siam, He is to have the government of the district, to 

 enable him to carry out his designs. As the river Kra is the boun- 

 dary between British Birmali and Siam, it is probable that the pro- 

 duct of these tin mines will be carried to England. 



Dr. Feuchtwanger. — The tin mines of Mexico prove to be very 

 rich. 



Pkepakatiox of J^itkogbn. 



An Italian chemist, Mr. Massino Levy, has devised an admirable 

 method for preparing nitrogen gas. It consists in heating bichromate 

 of ammonia in a retort, when the salt is transformed into the green 

 sesqui oxyd of chromium; the remaining oxygen, having united 

 with hydrogen of the ammonia, forms water; while the nitrogen of 

 the ammonia, on being isolated, assumes its natural state as a gas. 

 A good deal of random discussion followed the reading of this note, 

 but no very definite conclusion was reached. 



