Smith, "General Chemistry for Colleges," page 416, says: Cupric sulfide may be obtained "by cautiously heating copper with excess sulfur a t 1 1 4 O . At higher temperatures i t gives off sulfur." Other authorities may be cited.= It appears therefore that cuprous sulfide is formed and the results indicated above confirm the formula CupS rather than CuS as often stated in texts.s With regard to possible oxidation, it may occur, but since the product which might be formed would have practically the same molecular weight as the original, there would be only a very slight difference.
+ o * +2 c u o + S
Cu,S 159.20
159.14
With regard to the possibility of a small core of unaffected copper, we have never found any indication of this. The product crumbles easily to bits in the fingers which it would hardly do if a fine core of unaffected wire remained. This experiment has been done several thousand times a t the English High School with average results varying but very slightly from year to year. At the proper time, the average of results obtained during the previous month of laboratory work may be made the basis for a confirmatory study of the Law of Definite Proportions. The briefness of time required for the experiment, the generally good results obtained, the ready availability of the materials, the simplicity of the apparatus used, and the operations involved combine to make this experiment one which teachers may well consider in preparing their list of laboratory studies. a Sneed, "General Inorganic Chemistry," p. 260, Ginn & Co. a "Chemistry of Common Things," p. 45, Allyn & Bacon; "Chemistry for Secondary Schools," p. 174, Ambrose & Co.; "Elements of Chemistry," p. 160, Macmillan.
Liver Chemistry Studied to Aid Medical Science. Liver, once given away by country butchers, has climbed into a top place in the aristocracy df the meat market, and chemists are ardently wooing i t t o learn its secret. This is the result of the recently discovered value in the treatment of human ills, especially pernicious anemia, Dr. David Klein of Chicago told the Institute of Chemistry of the American Chemical Society recently. At present pernicious anemia sufferers in pursuit of health have to eat liver by the pound, the speaker said, hut it is the hope of the chemist to find out the particular small fraction of its mass that makes i t "good far what ails you." His ambition is to get it out in pure form, analyze it, give it a long, hard name and then make i t in the chemical factory. And what he hopes to do for liver he also wants to do for the thyroid, suprarenal, pituitary, parathyroid, and all the other ductless glands whose influence on our health and often on our very character is very pronounced, though as yet only partly understood.-Science Senice
