376 Intelligence and Miscellaneous Articles. 



latter should act directly on the needles of the galvanometer. In 

 order to show this the author placed two insulated flames somewhat 

 higher than the magnetic meridian, and connected these flames by- 

 wires at right angles to the meridian with the earth and the electrical 

 machine respectively. The coils of the galvanometer should be 

 either closed or altogether removed, otherwise the current divides 

 in the coils ; the metallic galvanometer with a bell-magnet gave a 

 deflection of 5-7 divisions as soon as the machine was set to work. 

 The distance of the flames was 920 millim. The direction of the 

 current is changed when the current flows below the galvano- 

 meter, as required by Ampere's laws. — Journal of the Russian 

 Physical and Chemical Society (7) xviii. 1886. From an abstract 

 in Beiblatter der PhysiJc, vol. xi. p. 369. 



METHOD OF OBSERVING THE ACTION OF MAGNETS ON LIQUIDS. 

 BY S. T. MOREHEAD. 



Some weeks ago one of my students, Mr. J. C. Child, and my- 

 self were working with a diamagnetic instrument, simply repeating 

 well-known experiments. Pliicker's method of observing the dia- 

 magnetism of liquids having failed in our hands to give satisfactory 

 results, we hit upon a method which was new to us and which was 

 very satisfactory. Into a glass tube of about four or five milli- 

 metres internal diameter a small quantity of liquid was introduced 

 forming a short cylinder. This tube was placed horizontally at 

 right angles to the line joining the poles of the magnet with the 

 liquid nearly between the poles. When the current was turned 

 on, the liquid was very evidently repelled. Water was repelled 

 through a distance of about half a centimetre ; wood-spirit through 

 a greater distance. By moving the tube in the direction of its 

 length the wood-spirit could be pushed any distance through the 

 tube. The amount of motion is of course a function of the 

 resistances due to adhesion and friction as well as of the repul- 

 sive force. The attraction of liquids is easily shown by the same 

 method. 



A single modification of the above plan of proceeding is to in- 

 cline the tube slightly so as to make the liquid flow toward the 

 poles. If the acquired velocity be not too great the magnet acts 

 as a break to stop the motion. It is well to bend the tube up a 

 little at each end to prevent the liquids from flowing out. This 

 method is well adapted for projection so as to be seen by large 

 audiences. — Silliman's American Journal, September 1887. 



