1. Biallyl has been prepared by the action of sodium 5 or aluminum 6 on allyl iodide; from allyl mercuric iodide by dry distillation 7 or by the action of potassium cyanide solution; 8 by the action of magnesium on allyl bromide, 4, 9 allyl chloride, 4, 10 allyl iodide, 11 or 1,2,3-tribromopropane; 12 and from diallyl ether by the action of sodium