Prof. E. Edlund's Investigation of the Electric Light. 103 



Q = UE = 2 S . C 4 H 8 . H 2 0, in which the letters signify atoms, 

 some of which are half molecules, some whole molecules, and 

 one represents the sixth part of a molecule. 



Q=U.E = OS*.C 2 H 4 .H0*, in which the same letters, all 

 without any exception, signify molecules, each of which, when 

 it stands by itself, occupies a volume. U E indicates two vo- 

 lumes changed into one. C 2 H 4 HOi indicates 2 + 4 + 1^ = 7 J 

 volumes changed into one, and OSi . C 2 H 4 HO* indicates 8|- 

 volumes changed into one. 



Applications of this system to express chemical reactions are 

 given in the Philosophical Magazine for April 1864. It ren- 

 ders unnecessary the tedious ever recurring verbal description of 

 constitution by volume given by chemical writers ; and while 

 thus saving space, would, I am fully convinced, put an end to 

 the confusion which is still admitted to exist by M. Wurtz (see 

 last sentence of the first part of the recently published c Intro- 

 duction to Chemical Philosophy '), in spite of the new system of 

 notation which he proposes. 



XII. Investigation of the Electric Light. 

 By Professor E. Edlund*. 



1. T7WERY natural force has a definite quantitative action. If 

 -E-J under one set of circumstances a force exerts an action 

 which in any respect differs from that which the same force 

 produces under other circumstances, both actions must still be 

 quantitatively equal. If the force produce both actions simul- 

 taneously, the sum of the actions must be as great as the quan- 

 titative value of one of them when this alone is produced. It 

 is of course presupposed that the time during which the force 

 acts is equal in all these cases. The voltaic current exerts, as 

 is well known, various actions ; it produces heat and light, de- 

 composes compounds which are conductors of electricity, excites 

 magnetism, and acts upon bodies already magnetic, induces 

 voltaic currents in adjacent conductors, &c. In a certain sense 

 it may be said that the first and direct action of the voltaic cur- 

 rent is the production of heat, because this always accompanies 

 it, while the other actions require certain conditions for their 

 fulfilment. It is known from trustworthy experiments that the 

 heat produced is proportional to the square of the intensity of 

 the current multiplied by the resistance. The entire quantity 

 of heat which is developed by the current is therefore propor- 



* Translated from Poggendorff's Annalen, No. 8 (1867); having been 

 read before the Royal Academy of Sciences in Stockholm. 



