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A new use for the aniline colors
372
Editorial.
factory ; some of them differing very ~'idely. As an instance of t h i s difference in opinion, it may be said that the famous astronomer a/n'd spectroscopist, Pater Secchi, maintains this temperature to be a b o u t ten million degrees Centigrade. At a recent sgance of the French Academy, in defending his e s t i mate vgainst the much lo~'er figures of :Ericsson, ZiJllner and F a y e , St. Claire Deville asserted that he was engaged in investigating t.he subject, and that his results fixed the temperature at about three o r four times the melting temperature of platinum, about 6000 to 8 0 0 0 degrees (C.) Mr. ¥aulle also announced an ingenious theory u p o n the same subject, fixing the debated figure at 10,000 degrees ( C . ) ]Finally M. Fizeau stated that, having compared the solar light w i t h that of the carbon points of the electric light, he had been able to e s timate that the former was about three times as intense as the l a t t e r . and hence, assuming the relative calorific intensity to be in p r o p o r tion to the luminous intensity, he had arrived at the figure of 8 0 0 0 degrees (C.) as the correct one.
A New Use for t h e A n i l i n e Colors.--Mr. F. S p r i n g m k i h l recommends the use of alcoholic solutions of various gums ( s h e l l a c , saudarach, &c.), to which various aniline colors have been added, ir~ coloring all kinds of paper, leather, linen, &c.* The gum solution, which should be thin, penetrates entirely t h r o u g h tlle paper and gives to it an even tone. The operation is s i m p l y t o place the coloring liquid in a shallowdish, and to draw the substarJce to be colored through it, which is subsequently hung up t o d r y ; w h e r ~ dry another color can readily be produced upon one of the s i c l e s . Sandarach is said to produce matt; shellac and most other g u m s , a lustrous color. By adding to the lac solutions a small quantit2~r o f some etberial oil, the substance may at the same time be perfurn ecl. By judiciously mixing several of the lacs, any desirable tin~ can b e produced. A Pressure G u a g e for G u n s . - - T h e principle suggested b y Tresca's experiments on the flow of solids has, we are informed, b e e n applied in practice for determining the pressure produced in the b o r e of large guns.-~ A cylindrical bole, bored into th e gun, is filled b y a block of lead, supported behind "by a steel bl0ck, through which i s a * Zeitschr. f. Farberei,:1871. No. 41. t Eng. and Min. Jom-n., xiii, 283.
Editorial.
factory ; some of them differing very ~'idely. As an instance of t h i s difference in opinion, it may be said that the famous astronomer a/n'd spectroscopist, Pater Secchi, maintains this temperature to be a b o u t ten million degrees Centigrade. At a recent sgance of the French Academy, in defending his e s t i mate vgainst the much lo~'er figures of :Ericsson, ZiJllner and F a y e , St. Claire Deville asserted that he was engaged in investigating t.he subject, and that his results fixed the temperature at about three o r four times the melting temperature of platinum, about 6000 to 8 0 0 0 degrees (C.) Mr. ¥aulle also announced an ingenious theory u p o n the same subject, fixing the debated figure at 10,000 degrees ( C . ) ]Finally M. Fizeau stated that, having compared the solar light w i t h that of the carbon points of the electric light, he had been able to e s timate that the former was about three times as intense as the l a t t e r . and hence, assuming the relative calorific intensity to be in p r o p o r tion to the luminous intensity, he had arrived at the figure of 8 0 0 0 degrees (C.) as the correct one.
A New Use for t h e A n i l i n e Colors.--Mr. F. S p r i n g m k i h l recommends the use of alcoholic solutions of various gums ( s h e l l a c , saudarach, &c.), to which various aniline colors have been added, ir~ coloring all kinds of paper, leather, linen, &c.* The gum solution, which should be thin, penetrates entirely t h r o u g h tlle paper and gives to it an even tone. The operation is s i m p l y t o place the coloring liquid in a shallowdish, and to draw the substarJce to be colored through it, which is subsequently hung up t o d r y ; w h e r ~ dry another color can readily be produced upon one of the s i c l e s . Sandarach is said to produce matt; shellac and most other g u m s , a lustrous color. By adding to the lac solutions a small quantit2~r o f some etberial oil, the substance may at the same time be perfurn ecl. By judiciously mixing several of the lacs, any desirable tin~ can b e produced. A Pressure G u a g e for G u n s . - - T h e principle suggested b y Tresca's experiments on the flow of solids has, we are informed, b e e n applied in practice for determining the pressure produced in the b o r e of large guns.-~ A cylindrical bole, bored into th e gun, is filled b y a block of lead, supported behind "by a steel bl0ck, through which i s a * Zeitschr. f. Farberei,:1871. No. 41. t Eng. and Min. Jom-n., xiii, 283.