Proceedings of the P olytechnio Association. 1061 



pure' there is perhaps not much necessity of it, but in cities and on 

 the banks of streams where there are very deleterious matters, this 

 system of ventilation would be very requisite. 



Plating Steel with Nickel. 

 Mr. Smith, of Boston, made some remarks on the process of Dr. 

 Isaac Adams, Jr., for coating steel with nickel. He exhibited several 

 pieces of cutlery plated with that metal. The advantages, he said, 

 which are claimed for this process are, in the iirst place the nickel is 

 cheaper, as it can be procured for three or four dollars a pound. And 

 in the second place it is less liable to tarnish from exposure to the atmos- 

 j^here than silver, and if subject to wear, is much harder and more 

 durable than it, while the color is much the same as that metal. 

 Some fifteen or twenty years ago, Smee, in England, described this 

 process, and even men in this country have done it. The coating of 

 cutlery is nov*", however, done with nickel very beautifully in Boston. 

 But Dr. Adams has gone beyond what has been done heretofore. 

 Formerly only a thin film of nickel could be deposited, JSTothing 

 like depositing nickel in the reguline state, as it is called, has been 

 done previous to Dr. Adams. The specimens here shown are 

 evidences of the perfection to which it is brought. In the coating of 

 polished sheet iron. Dr. Adams has done remarkably well. He was 

 sorry he had not some specimens of this kind with liim. Some that he 

 had in Boston were one-eighth of an inch thick. Dr. Adams has per- 

 fected the process so far as to be able to plate cutlery with nickel with the 

 same facility as copper is deposited. The nickel is so hard that it is found 

 as hard to scratch it as the steel. It is a cliemical deposition and 

 therefore does not injure the temper of the steel. It is deposited by 

 tlie ordinary Smee battery, single cell. Copper is very easily deposi' 

 ted in the reguline state ; a pure deposit of copper can be oljtained 

 within a very wide limit, while some of the other metals can be clone- 

 so in a very narrow limit, depending on the intensity of the current 

 and the strength of the solution. It is a scientific question of deep 

 importance to know what causes this. He believed that this process 

 of depositing nickel will throw much light on the process of electro 

 deposition of other metals. He had in Boston some specimens 

 covered witli cobalt. These perhaps were the first specimens tliat 

 have been obtained. The color Dr. Adams says is better than 

 nickel. With the improvements of Dr. Adams he thought iridium 

 could be deposited by electricity. By the deposition of copper it is 



