JUNE, 1952
AN EXPERIMENT ON THE L A W OF MULTIPLE PROPORTIONS ANYONE who desires a laboratory experiment to illustrate the law of multiple proportions will find it quite satisfactory to use the reduction of cuprous and cupric oxides. Weighed samples can be placed in horizontal hard-glass test tubes and reduced by heating in a stream of illuminating gas. The most important precaution to observe is to be sure that the product is cooled while the gas is still running into the tube. The 2:l valence ratio is advantageous because of its simplicity and ease of recognition by students in spite of small errors in the final results. Also, the regularity of the gas flow is decidedly helpful.-John H. Seerist, Wayne University, Detroit, Michigan.
