TRANSACTIONS OP SECTION B. 115 



v?here there was no magnesium, indicating decomposition of 

 the zinc ethyl. There was a great deal of gas on opening the 

 tube. The top part of the tube was then cut off, and a con- 

 denser filled with hydrogen was attached, after which the tube 

 ■was heated in an oil-bath up to 220". A few drops came over 

 which, on treatment wdth water, yielded zinc hydroxide ; but 

 no trace of magnesium hydroxide was found. The black deposit 

 in the tube was metallic zinc. On adding water to the resi- 

 due left in the tube there was a copious generation of gas, 

 which was, however, found to be pure hydrogen, due evidently 

 to the action of a zinc-magnesium couple. 



Experiment VIII. 



was an attempt to make magnesium ethyl by the action of 

 zinc ethyl on anhydrous magnesium iodide according to the 

 equation, — 



MgL+ Zn(C2H5). = Mg(C,H.)o + Znlo. 

 .11"5 grams of zinc ethyl were sealed up with about 25 grams 

 of magnesium iodide. The action began at 130°, when a slight 

 blackening took place, and appeared to be complete after 

 heating for some time to loO°-160^. On opening the tube 

 there was a moderate rush of gas. The tube was attached to 

 a condenser as in VII., and was heated in an oil-bath up to 

 200^. A small amount of liquid distilled over, which gave a 

 white precipitate with water. This, however, consisted only 

 of zinc hydroxide. The residue in the tube was metallic zinc, 

 together with the unacted-on magnesium iodide. 



Experiment IX. 



This was an attempt to obtain the ethide by heating mag- 

 nesium with anhydi'ous ethyl-ether, the equation representing 

 the action being, — 



2:\Ig+(C.,H5)20 = Mg(C2H,), + MgO. 



It was doubted beforehand whether this reaction would 

 take place, as, although magnesium has a great affinity for 

 oxygen, that affinity is not very active till temperatures are 

 reached at which the ethyl groups would be broken up. These 

 doubts were fully borne out by the result. 



One gram of magnesium was sealed up with the right 

 amount of anhydrous ether. There was no action, even on 

 heating to 260°. At 290° the tube broke, but no fumes nor 

 ethide smell were noticeable. 



The nett result : of all my experiments is that I have not 

 found it possible to prepare magnesium ethide. 



