CHEMICAL SCIENCE. 201 



this circumstarLce there is produced between a liquid and a gas (the 

 chloride of gold and hydrogen.) when platinum is present, an action 

 of the same kind as between oxygen and hydrogen, under the influ- 

 ence of the same metal. 



3d. A piece of wire, with a sheet of gold under the same conditions, 

 does not furnish any noticable effect. 



4th. A voltaic pair may be formed with a single liquid, two sheets 

 of platinum and one gas (hydrogen,) but this latter to be in contact 

 with one of the sheets and the liquid; by uniting several pairs there is 

 then a gas battery composed of a single gas, one metal and one liquid. 

 Hitherto it had been laid down as a law, that with the platinum and 

 acid solution, two gases (oxygen and hydrogen) were necessary to 

 obtain this result ; only the elements of the battery formed with the 

 chloride of gold, have a feebler intensity of action than the usual 

 gas pairs. 



5th. The solution of chloride of gold, chemically pure, may there- 

 fore be considered definitively as superseding the acid solution and 

 oxygen in the gas battery. The remarkable effects that are manifested 

 in this circumstance should not be confounded with those that would 

 be produced by certain gaseous solutions or liquids, such as nitric 

 acid absorbing hydrogen at the ordinary temperature, without the 

 appliance of platinum. 



OX THE SPHEROIDAL STATE OF BODIES. 



AT a lecture before the Royal Institution, England, M. Boutigny 

 remarked that the simple phenomena of the subject would seem to 

 have necessarily attracted attention from the most ancient times, and 

 endeavoring to discover some record of the fact, he had found the 

 possible expression of it in the Wisdom of Solomon, xix. 20 : 

 u The fire had power in the water, forgetting his own virtue ; and the 

 water forgat his OAvn quenching nature." Eller and Leidenfrost, 

 however, about the middle of the last century, first truly observed 

 the simple phenomena ; but nothing had since been done, either to 

 increase our knowledge of the singular facts, or to suggest an explan- 

 atory theory concerning them. M. Boutigny then exhibited the 

 experiments which he had recently made. He placed some nitrate 

 of ammonia, which is inflammable at a very low temperature, upon a 

 capsule of platina, greatly heated, but it assumed the spheroidal con- 

 dition without ignition. On removing the lamp, however, and when 

 the substance was cooled down to the ordinary temperature, it ignited. 

 The beautiful violet colored vapor of iodine was produced also in the 

 same manner, as also distilled water, which passed into steam as soon 

 as the metal disc was sufficiently cooled. Pie then proceeded, by 

 experiment, to show how the fact as relates to water, readily explains 

 the occasional bursting of steam boilers, when, by the cooling of the 

 boiler after the introduction of water into it wdien overheated, the 

 contents are immediately and violently converted into steam. 



