Mr. G. B. Buckton on the Organo-metallic Radicals. 215 



heat being raised by degrees until gaseous products appeared. The 

 distillate, after being well washed, was rectified by the thermometer, 

 and in this manner the radical was obtained in a state of purity. 

 Iodide of mercurous ethyle may be formed so easily by diffused day- 

 Ught, and its action is so gentle on zinc-ethyle, that its use offers 

 greater conveniences to the operator than are afforded by any of the 

 substances previously mentioned. 



For obvious reasons, a similar choice of materials is recommended 

 for preparing mercuric methyle. 



Action of Zinc-ethyle on Chloride of Lead, 



The close relations which exist between the three metals, lead, 

 mercury, and silver, in their equivalent weights, salts, and other 

 characters, lead the author to anticipate success in forming their 

 ethyle bases. 



The existence of the lead radical might indeed be considered as 

 certain, since various salts of complicated structure have been made 

 known to chemists through the experiments of M. Lowig, on the 

 alloy of lead and sodium, under treatment with iodide of ethyle. 



The principal product obtained by him, and the only one appa- 

 rently analysed, had a grouping similar to a sesquichloride. The 

 formula ascribed by him to the radical plumbethylium is Pb, ((11^115)3. 

 I have attempted to form the iodide of this radical by exposing 

 sealed tubes, containing granulated lead and iodide of ethyle, to the 

 sun's rays, but without success. No better result was obtained by 

 substituting bromide of ethyle for the iodide, and no change could 

 be induced even when these tubes were heated strongly with high- 

 pressure steam. 



M. Lowig's method was not resorted to, from the supposition that 

 the action of zinc-ethyle on a mixture would only give rise to radicals 

 of various constitution, which it might be impossible afterwards to 

 separate, except by working on a large scale, which, considering the 

 costliness of the materials, had its disadvantages. Perhaps success 

 might attend the use of one of Dr. Frankland's mirrors for concen- 

 trating the sun's rays. 



For obtaining the lead-radical, recourse was had to well-dried 

 chloride of lead, which was introduced into a flask containing zinc- 

 ethyle. The chloride immediately turned black, from the deposit of 

 metallic lead, whilst moderate heat was disengaged. An excess of 

 chloride was used, and the mass incorporated by stirring with a 

 glass rod. After applying a gentle heat for a few minutes, the 

 floating clear liquid was pijietted off. This substance is apparently 

 a compound of zinc-ethyle and the lead radicals. It fumes slightly 

 in the air, and no digestion with chloride of lead appeared to resolve 

 it entirely into the lead base. 



A great jjart of the zinc-ethyle, however, is removed by subsequent 

 distillation ; but the temperature should not be permitted to rise 

 above 140° or 1.50° C. The substance in the retort is then treated 

 with water and dilute hydrochloric acid, when the radical separates, 

 and sinks in the form of colourless drops. When distilled cautiously, 



