226 Royal Society : — 



the sodium, was next introduced, and the tube hermetically sealed. 

 So prepared, the apparatus was afterwards placed m cold water, and 

 left therein for several days, being cautiously shaken up at intervals. 



During this time the following changes were noted in the contents 

 of the tube. The sodium became coated with zinc, and gradually 

 disappeared, whilst the total volume of the solid and liquid contents 

 diminisbed considerably. The liquid became also viscid, and some- 

 times separated into two portions uon-miscible with each other, be- 

 coming, however, homogeneous as the operation advanced. There 

 was no evolution of gas. 



After the lapse of some days the apparatus was found to contain 

 metallic zinc and a clear colourless liquid. The former was weighed 

 and found to correspond to the sodium dissolved, one equivalent of 

 zinc being precipitated for each equivalent of sodium dissolved. 



The clear liquid was made the subject of special examination. It 

 consisted of zinc-ethyle holding in solution a crystalline compound 

 containing sodium, zinc, and ethyle. It was inflammable to the last 

 degree, burning explosively, on exposure to the air, with a yellow 

 flame, and leaving a very alkaline residue. Owing to its extreme 

 tendency to become oxidized, its manipulation presented great diffi- 

 culties. It was requisite to decant it into bulbs filled with dry hy- 

 drogen or coal-gas ; and since heat produced partial decomposition, 

 the bulbs had to be double, so that the heated bulb might not receive 

 the liquid. 



The clear liquid deposited large quantities of beautiful crystals 

 when cooled to zero ; and when gently warmed in a stream of dry 

 hydrogen gas, so long as zinc-ethyle came off it yielded also a mass 

 of crystals. Some crystals were prepared in the latter manner ; they 

 fused at about 27° C, but once fused they remained fluid at several 

 degrees below that point. Numerous analytical determinations 

 prove that these crystals contain two equivalents of zinc for every 

 equivalent of sodium, and th^t their formula is 



Na 1 o/Zq 



The reaction by which they are produced may be thus expressed : 



^ Zn 1 ,Nal Zn"! , ., /^Na "I ^ / Zn \ • 

 ^ C,B, I +Na j =Zn | + ^ Uh, j ' ^ | C,H j* 



For the body Na C^ H, I propose the name sodium-ethyle, and for 

 the crystals that of double compound of sodium-ethyle with zinc- 

 ethyle. 



Many attempts were made to obtain sodium-ethyle free from zinc- 

 ethyle, but without success. 



By distillation it was found to be equally impossible either to 



distil off p TT [ from the crystals, or to distil off all p, „ \ so as 



to leave pure p t^ [ behind. When the crystals are moderately 



heated in a bulb, a singular phenomenon occurs. Gas is evolved, and 

 there remains behind metallic sodium, also metallic zinc, but no car- 



