according to the leakage formula, from the initial and final read- 

 ings of the galvanometer. If the two do not agree, the spring is 

 altered until they do; but its action is found to be very constant 

 and not to need alteration, except after taking the apparatus to 

 pieces for alteration. Several series of experiments are given, and 

 the results show the delicacy and accuracy of the method.— Phil. 

 Mag., ii, p. 321. e. c. p. 



12. Chemistry and Physics in America. Address /»/'"'<' ' / "' 

 American Chemical Society at its session on the ItioV <>;' last 

 November, by Prof. John W. Draper, its President.— The fol- 

 lowing is the latter half of the able address ,,(' Prof Draper, the 

 whole of which would here be cited if space allowed. " In our 

 own special science, chemistry, all that has been done has only 

 served to extend the boundary of what remains. The thousands 

 of analyses that have been made have brought us into a wilderness 

 of results. We have not been able to rise to a point of view .suf- 

 ficiently high to discover what is the true place of those results in 

 nature. YVe trv to represent on the paces of our books and on 

 blackboards formulas of the constitution of things, conscious all 

 the time that these are at the best only convenient fictions, which 

 must necessarily change as we gain a more perfect insight into 

 that grandest of all pi. -i ■>,, of Force in Spare, 



and the variations to which it is liable The geometry of chemis- 

 try is that of three dimensions, not of two. We have to consider 

 toe relation of points not situated on one plane, and hence it is 

 necessary to employ three axes of reference; nay, even more, we 

 cannot avoid the conception of the mathematical* method of qua- 

 ternions. Our inadequate information respecting the real group- 

 ing of atoms is followed as a necessary consequence by imperfec- 

 tion in our methods of nomenclature, the confusion in this respect 

 becoming, as we all too well know, every day worse and worse. 



And now while we have accomplished only a most imperfect 

 examination of objects that we find on the earth, see how, on a 

 sudden, through the vista that has been opened by the spectro- 

 scope, what a prospect lies beyond us in the heavens ! I often 

 look at the bright yellow ray emitted from the chromosphere of 

 the sun, by that unknown element, Helium, as the astronomers 

 have ventured to call it. It seems trembling with excitement to 

 tell its story, and how many unseeu companions it has. And if 

 this be the case with the sun, what shall we say of the magnifi- 

 cent hosts of the stars ? May not every one of them have Rp i ial 

 elements of its own - i d laboratory in itself? 



Lo k it tin .1 !-•< is in the sword-handle of Perseus ; in Cassiopeia, 

 a universe of stars on a ground of star dust ; in Hercules, of 

 which as astronomers say, no one can look at for the first time 

 through a great telescope without a shout of wonder — the most 

 superb spectacle that the eye of man can witness ! Look at the 

 double stars of which so many are now known, emitting their 

 _ rays, garnet, or ruby. ire. Each 



is in accordance with its own special physical conditions, though 

 all are under the same universal ordinance. 



