supervision of, and in co6peration with, the Bureau of Mines, and except for such work as was necessary for assessment work to hold claims, was nearly stopped. The Institute mined nearly the Iooo tons of ore contracted fo.r from the Crucible Steel Mining and Milling Company's claims in Long Park, Montrose County, Colo., and obtained 7° tons of concentrates, carrying about 3 per cent. of uranium oxide, by concentrating material carrying o. 7 per cent., which had been thrown on the dumps. The Institute fully accomplished its purpose to work out a practical process of producing radium at a cost much below the market price of the element and crystallized out radium salts containing 6 grammes of the element. It delivered during the year 3.oo6 grammes of radium (element) at a cost of $37,599 per gramme. Near the close of the year 1.2 grammes of radium (element) was contracted for by a private company for $132,ooo, or $I2O,OOO a gramme. This comparison shows the great success of the work of the Bureau of Mines. Its ore concentration method seems to have also been highly successful. After mining its quota of ore from the Crucible Steel Mining and Milling Company's property, the Institute came into, the market as a purchaser of ore. In the later half of the year Dr. W. A. Schlesinger and associates established a radium reduction plant in Denver. They acquired an interest in the Copper Prince claims, from which ore was mined, and bought a further quantity. Ore carrying about 5ooo pounds of uranium oxide, containing about 64o milligrammes of radium, was treated during the year. The Carnotite Reduction Company, made up of Dr. H. N. McCoy, of the University of Chicago, and associates, purchased from Galloway and Belisle a quantity of ore which had been stored in Placerville, Colo., and the radium will be extracted in Chicago. The company will mine ore from claims it has bought. The Standard Chemical Company did no work on its claims except that required by law, but in this work produced and shipped a quantity of ore from its properties in Colorado and Utah, and purchased, it is stated, a considerable number of claims. It was reported in December that the company had produced a total of 14 grammes of radium (elemental) and that its ore had averaged I. 7 per cent. uranium oxide. Probably between 4 and 5 grammes of this quantity was produced during I9I 5. The production of radium salts in this country during the year was probably nearly ~1 grammes. Only a small quantity of ore is thought to have been shipped to Europe during the year. J . S . McArthur & Co. shipped one lot of ore from its claims near Greenriver, Utah, to Glasgow, Scotland. P e p t o n e as an Addition A g e n t in S t a n n o u s A m m o n i u m O x a l a t e Baths. F . C . MaTHERS and B. W. COCKRU~I. (Proceedings of the American Electrochemical Society, April 27-29, i916. ) -
[J. F. I.
Tests of tin-plating baths by these investigators indicated that the best tin deposit is obtained from a sannous ammonium oxalate bath containing peptone as an addition agent. Without the peptone the deposit is of no value as a protecting coat, because it consists of projecting needle-like crystals. The effect of the peptone is very remarkable. As soon as it was added, the tendency to form the projecting, loosely-adhering crystals ceased and the deposits became so smooth and finely crystalline that thick cathodes (0.5 to I cm. thick) could be prepared, and so firm and coherent that shavings could be cut from the deposit with a knife. Clove oil, glue, gelatine, and formin, agents which have been found effective with other metals, were practically without any beneficial influence in preventing the formation of crystals. Carbon disulphide, even in small amounts, made the deposit spongy and non-adherent, a condition which persisted until the carbon disulphide was exhausted, when the deposit againbecame crystalline. The addition of peptone to the stannous ammonium oxalate bath is essential for the production of a thick, smooth, finely crystalline deposit of tin. No other tin bath (except possibly the sulphide, which was no,t tried)is known from which such a thick, smooth deposit can be obtained. A good composition of bath is : 5 per cent. stannous oxalate, 6 per cent. ammonium oxalate, ~.5 per cent. oxalic acid, and 0.25 per cent. peptone. The stannous oxalate may be easily made by precipitating a solution of stannous chloride with oxalic acid. The bath was run at room temperature at 0.4 amp6re per square deci, metre (3.6 per square foot). The solution must be stirred at intervals. Wireless A c h i e v e m e n t s at T u f t s College. ANON. (The Electrical Review and Western Electrician, vol. 68, No. 16, April 15, I 9 1 6 . ) - - T h e transmission of music by wireless with a small amount of power, giving a range of more than IOO miles, so that ships at sea have picked up tunes, has been brought about at the station of the American Radio & Research Corporation at Tufts College, Massachusetts, of which Harold J. Power is general manager. The mere fact of sending music to the distance mentioned is not of itself a remarkable feat, but by means of a novel method of introducing the sounds in the radiated waves, resulting in articulation and loudness in the waves received, a marked gain has been aohieved. T o provide the high-frequency current necessary, Professor Power employed an oscillon bulb, the invention of Lee de Forest, of New York. It is recognized that there are two important factors in the successful transmission of wireless telephone messages. One is the generating of high-frequency currents, and the other is the modulation in accordance with the voice or the music to be transmitted. It is the latter of these two problems that Professor Power is especially interested in, because the De Forest oscillon is recognized as a perfect means of generating the needed high-frequency current. It has been possible for some time to obtain sufficient power to