482 Intelligence and Miscellaneous Articles. 



which supports it, the platinum wire is raised to a white heat. 

 Undoubtedly, by using a greater number of elements and a longer 

 lever, the platinum wire would be melted. If the contact of the 

 poles of an electromagnet be suddenly made, the platinum wire be- 

 comes dark again. 



Instead of such an electromagnet I use a coil, in which I introduce 

 an iron cylinder, or a cylindrical bundle of iron wire, which I then 

 rapidly remove. The platinum wire, which had become cooled 

 while the core was being introduced, became red-hot upon its re- 

 moval. 



A voltameter introduced into the circuit instead of the platinum 

 wire, shows a less copious disengagement of gas when the magnetiza- 

 tion is produced, a more copious one when it ceases. 



The explanation of these phenomena is very simple : — When the 

 magnetization is produced there is developed in the exciting current 

 of the electromagnet an induction current which is inverse ; when 

 magnetization ceases, another induction current, a direct one, tra- 

 verses the same exciting current, which in both cases is closed. 



My object in publishing this note is to add a simple experiment, 

 easy to reproduce, to the numerous ones by which it can be esta- 

 blished that all work consumes heat, and that, inversely t all work can 

 be converted into heat. 



To break the contact of the electromagnet, or the iron cylinder 

 of the coil, a resistance which is opposed to their motion must be 

 overcome, a certain amount of work is then consumed ; the platinum 

 wire becoming more strongly heated indicates a production of heat in 

 the entire interpolar circuit. If, on the contrary, I bring the cy- 

 linder into the coil, if I bring near the armatures of the electro- 

 magnet the soft-iron contact, the current produces external work ; 

 the wire joining the poles is cooled. — Comptes Rendus, Feb. 25, 

 1867. 



TRANSPORT OF A BODY BY THE VOLTAIC CURRENT AND BY IN- 

 DUCTION CURRENTS. BY M. DANIEL. 



This action of electricity and its direction may be shown by the 

 following experiment : — 



If water be electrolyzed in a vessel the bottom of which is to- 

 lerably large and somewhat bulging in the centre, and into which a 

 globule of mercury has been allowed to fall, this globule is seen to 

 move away at the approach of the positive electrode ; by suitably 

 moving this, a continuous rotatory motion may be imparted to the 

 mercury. This observation has led to the following simple experi- 

 ments : — 



I fill with very slightly acidulated water a tube more or less 

 long, bent twice at right angles, and with a diameter of 10 to 15 

 milliras. It resembles a water-level. In the liquid is placed a 

 globule of mercury 2 to 3 centims. in length, and in the vertical 

 branches of the tube the electrodes of a battery are immersed. By 



