Proceedings of the American Academy of Arts and Sciences, Vol. 30

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Excerpt from Proceedings of the American Academy of Arts and Sciences, Vol. 30: From May, 1894, to May, 1895It is frequently convenient to be able to regulate within close limits the ¿ow of gas for the required temperature without further attention after lighting the jets. The device shown in Figure 2, which sug gested itself for this purpose, consists in attaching to the end of the gas valve by means of a screw thread a brass cap with an index of stout Copper wire moving in front of a graduated circle with a radius of about six inches.With glass tubes of large size, those we use are mm. Inside diameter, well sealed and with strict adherence to certain conditions which have elsewhere been described by A. W. Smith and me, * there is little danger of an explosion. The quantity of nitric acid should not be in excess of twenty times the weight of the substance taken, and after heat ing to 175° for fifteen hours the tubes are Opened, - best without remov ing from the furnace, resealed and heated again to 250° during five to ten hours. The serious objection to the Carius method for sulphur is the slow process of oxidation, and it seems hardly possible to hasten the Operation by raising the temperature, since glass tubes will not stand the great pressure.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.