1835. Sesquisulphata of Manganese. 371 



To what the yellow colour is owing, which this salt pos- 

 sesses I do not know. The solution of it in water is colour- 

 less, so that none of the manganese can be in the state of 

 red oxide. I could detect no oxide of zinc in the oxide of 

 manganese, and none could be extracted by digesting the 

 newly precipitated oxide in caustic potash. 



Article VI. 



Animal Heat. 



Becquerel and Breschet are at present engaged in a series 

 of experiments upon this subject. Their mode of deter- 

 mining the temperature of different parts of animal bodies 

 is by means of a thermo-electric multiplier, with needles 

 and probes formed of two different metals, soldered in cer- 

 tain^ points only. 



The needles are of two kinds, the most simple being com- 

 posed of two other needles, the one of platinum, or copper, 

 the other of steel, soldered at one of their extremities in 

 the direction of their lengths, each of them being about half 

 a millimetre (0*0196 inch) in diameter, and a decimetre 

 (3*93 inches) in length. One of these needles is introduced 

 into that part of the body whose temperature is to be deter- 

 mined, the soldered part being placed in the same medium. 

 The two free ends are then made to communicate with the 

 wires of the multiplier. The points of junction, platinum 

 and copper, steel and copper, if the platinum and steel needle 

 is employed, or the points of junction of steel and copper, 

 if the steel and copper needle is employed, are placed in 

 melting ice, in order that the temperature may remain con- 

 stant. The magnetic needle then deviates, in consequence 

 of the difference of temperature which exists between the 

 point examined and zero. Experience shows that the maxi- 

 mum effect is found between 0° & 25° ; therefore, before 

 commencing the experiment, the multiplier may be so 

 adjusted that the needle shall stand between 20° &: 25°, in 

 order that the most minute deviations may be noted. When 

 the magnetic needle has acquired a fixed equilibrium, the 

 probe is withdrawn from the part examined, and the corre- 

 sponding soldered part is plunged into a water-bath, of 

 which the temperature is raised until a deviation is pro- 



2 B 2 



