240 Royal Society. 



metals found in nature as are of a soft colloid description, par- 

 ticularly native iron, platinum, and gold, by an investigation of 

 the gases which they hold occluded, such gases being borrowed 

 from the atmosphere in which the metallic mass last found itself 

 in a state of ignition. The meteoric iron of Lenarto appeared to 

 be well adapted for a trial. This well-known iron is free from 

 any stony admixture, and is remarkably pure and malleable. It 

 was found by "Wehrle to be of specific gravity 7*79, and to con- 

 sist of — 



Iron 90883 



Nickel 8-450 



Cobalt 0-665 



Copper 0-002 



From a larger mass a strip of the Lenarto iron 50 millimetres by 

 13 and 10 millimetres, was cut by a clean chisel. It weighed 45*2 

 grammes, and had the bulk of 5*78 cubic centimetres. The strip 

 was well washed by hot solution of potassa, and then repeatedly 

 by hot distilled water, and dried. Such treatment of iron, it 

 had been previously found, conduces in no way to the evolution 

 of hydrogen gas when the metal is subsequently heated. The 

 Lenarto iron was enclosed in a new porcelain tube, and, the latter 

 being attached to a Sprengel aspirator, a good vacuum was ob- 

 tained in the cold. The tube being placed in a trough combustion- 

 furnace, was heated to redness by ignited charcoal. Gras came off 

 rather freely, namely — 



In 35 minutes 5*38 cub. centims. 



In 100 minutes 952 „ 



In 20 minutes 163 „ 



In 2 hours 35 minutes 1653 „ 



The first portion of gas collected had a slight odour, but much 

 less than that of the natural gases occluded by ordinary malleable 

 iron. The gas burned like hydrogen. It did not contain a trace 

 of carbonic acid, nor any hydrocarbon vapour absorbable by fuming 

 sulphuric acid. The second portion of gas collected, consisting 

 of 9*52 cub. centims., gave by analysis — 



Hydrogen 8*26 cub. centims 85*68 



Carbonic oxide 043 „ 4*46 



Nitrogen 0'95 „ 9*86 



9-64 „ 10000 



The Lenarto iron appears, therefore, to yield 2 '85 times its 

 volume of gas, of which 86 per cent, nearly is hydrogen. The 

 proportion of carbonic oxide is so low as 4 j per cent 



The gas occluded from a carbonaceous fire, by iron, is very 

 different, the prevailing gas then being carbonic oxide. For 

 comparison a quantity of clean horseshoe-nails was submitted to a 

 similar distillation. The gas collected from 23*5 grammes of metal 

 (3*01 cub. centims.) was — 



