Prepd from aluminum silicide and hydrochloric acid or by electrolysis of an aq soln of sodium, ammonium, manganese, or ferrous chloride using an aluminum-silicon alloy as the positive pole: Buff, W"ohler, Ann. 102, 128 (1857); from magnesium silicide and HCl: W"ohler, ibid. 106, 56 (1858); Stock, Somiesky, Ber. 49, 111 (1916); from zinc silicide and acid: Deville, Caron, Compt. Rend. 45, 163 (1857); from lithium silicide and acid: Moissan, ibid. 135, 1284 (1902); from magnesium silicide and ammonium bromide or chloride in liquid ammonia: Johnson, Isenberg, J. Am. Chem. Soc. 57, 1349 (1935); Clasen, DE 926069 (1952); Angew. Chem. 70, 179 (1958); from lithium aluminum hydride in ether and silicon tetrachloride: Finholt et al., J. Am. Chem. Soc. 69, 2692 (1947); from silica gel, aluminum oxide and hydrogen: Jackson, US 3068069 (1962 to du Pont); from silicon tetrachloride and sodium aluminum hydride: Mason, Kelly, US 3043664 (1962 to Allied Chem.). Purification: Jacob, Trenner, US 3019087 (1962 to Merck & Co.); Shoemaker, Sumrell, US 3041141 (1962 to Baker Chem.).