698 Chronicles of Science. [Oct., 



" IV. Both the heat elements are set free, under the form of the 

 two electricities, during ordinary combustion, but only one of them 

 during galvanic action. 



" V. Motion is never produced, except by decomposition of heat, 

 or by liberation of the calorific elements, during chemical action, 

 which is true, even when the decomposition is due to electricity or 

 electro-magnetism. And motion is never destroyed without heat 

 being formed again, except when the calorific elements are prevented 

 from uniting." 



The second communication on this subject is from Mr. A. J. 

 Cameron. In this letter the author says, that many years ago, in 

 a paper which was read by Professor Gregory, and also by several 

 others, he demonstrated that the two electricities when uniting formed 

 caloric ; but more than this was shown, for it would appear that after 

 they had combined, they formed all hinds of matter, solid, liquid, and 

 gaseous ! We think Mr. Cameron has certainly no reason to accuse 

 either Mr. Martin or Mr. McGauley of having anticipated him in 

 that discovery. ' 



M. Becquerel has published some new observations on thermo- 

 electric piles of sulphide of copper. The author first described the 

 way in which he prepared the sulphide of copper. He places a 

 quantity of sulphur in a crucible and heats it to fusion. When this 

 occurs, which is known by the escape of sulphur vapour, he immerses 

 in the melted sulphur a plate of copper previously heated to dull red- 

 ness, and leaves it in the crucible until all the sulphur is volatilized. 

 He then removes the plate of copper coated with sulphide, cools it 

 rapidly by dipping it into cold water, and finally detaches the coating 

 of sulphide. This is then fused and run into bars or plates for the 

 pile. As a negative element he employs maillechort (a nickel alloy 

 resembling argentine). The author remarks that bars made of the 

 same sulphide show a very unequal action, and that they should be 

 tested before employed for a battery. In a note he mentions that 

 Rhumkorff has found that the addition of irth of sulphide of antimony 

 renders the action regular, although it somewhat diminishes the 

 power. The ends of the bars of sulphide must be encased by the 

 metal to prevent reduction when heat is applied direct, as by a gas 

 flame. The author next proves that the current is developed by 

 differences of temperature, and not by any chemical change in the 

 sulphide, by showing that a battery has kept in action for a month 

 with one extremity near the melting point of lead without loss of 

 weight in the bar of sulphide of copper. M. Becquerel goes on to 

 compare the electro-motive force of this battery with other thermo- 

 electric piles, and shows that its power is much higher than that of 

 the alloy of antimony and zinc employed by Marcus. It is only 

 available, however, when the effects of tension are required. 



In some curious statistics on the subject of death by lightning, 

 given in a note by M. Boudin before the French Academy, it appears 

 that during the period 1835-1863, 2,238 individuals were killed in 

 France. The most in one year was 111 ; the fewest, 48. Among the 



