ORGANIC BODIES CONTAINING METALS. 
427 
Both these causes probably contribute to produce the excess of hydride of ethyl ; 
but the very small amount of gaseous products, compared with the solid ones, con- 
vinced me that the production of the former is only an accidental circumstance, 
which, however it may be interpreted, does not at all affect the principal reaction, 
viz. the formation of iodide of stanethylium. The gases, evolved by the action of 
light upon iodide of ethyl and tin, are perfectly similar to those obtained by the 
action of heat. 
Stanmethylium and stanamylium are formed when the iodides of methyl and amyl 
respectively are exposed to the action of light in contact with tin ; their salts are 
isomorphous with those of stanethylium ; but I have not yet completed the investi- 
gation of these bodies. 
Action of Zinc upon Iodide of Methyl. 
When iodide of methyl and zinc are exposed to a temperature of about 150° C. in 
a sealed tube, the zinc gradually dissolves with the evolution of gas, whilst a mass 
of white crystals and a colourless mobile liquid, refracting light strongly, occupy, 
after a few hours, the place of the original materials. The gas, evolved on breaking 
off the capillary extremity of the previously exhausted decomposition tube, was col- 
lected and preserved over sulphuretted water in the manner already described : I 
will refer to this gas again under the name of a. On cutting off the upper 
portion of the decomposition tube and pouring cold distilled water upon the mobile 
liquid and white mass of crystals just mentioned, a very violent action ensued, and a 
column of flame several feet high shot up momentarily from the mouth of the tube; 
but the action soon became more moderate, and a cork and gas-delivering tube 
being fitted into the decomposition tube, the gas, after all atmospheric air had been 
expelled, was collected and preserved in an apparatus similar to that used for the 
gas a. I will call this second gas (3. 
Zin cm ethy Hum. 
From a preliminary experiment, it was ascertained that the gas evolved on open- 
ing the decomposition tube possessed, before contact with water, a most insupport- 
able and very peculiar odour, and that, when ignited or brought in contact with 
pure oxygen gas, it burnt with a greenish blue flame, producing dense white fumes: 
when a porcelain plate was held in this flame, it immediately became coated with a 
jet black deposit, surrounded by a white ring; this black deposit dissolved in dilute 
hydrochloric acid with evolution of hydrogen gas, and the solution was found to 
contain chloride of zinc. Hence it was evident that a volatile or gaseous compound 
of zinc was present amongst the products of decomposition, and this was soon found 
to reside in the mobile liquid above mentioned ; for on inverting the tube and allow- 
ing a few drops of the liquid to escape, it inflamed spontaneously the instant it came 
in contact with the air, and produced, by its combustion, large quantities of oxide of 
