to all courses and lectures and will be used to defray the program expenses, will be $10.00 for one week, $20.00 for two weeks, $25.00 for three weeks, and $30.00 for four weeks. College credit up to six semester hours is included in the $30.00 fee, but six weeks are needed for credit. Members of the Institute and their families will also be interested in the full program of lectures and entertainments given by the Summer Session of the Pennsylvania State College which will be in session a t the same time. These include lectures by Dr. H. V. Pike, Grace Hazard Conkling, Clayton Hamilton, Edward Davison, Dr. F. I,. Pattee, and Hamlin Garland. There will be recitals and concerts by Stella Anderson, Vera Poppee and James Woodside, and dramatic performances by the Penn State Players, the DeVereaux Players, and by U. I,. Granville. The institute of French Education, under M. G. P. Fougeray, will have a number of interesting French sessions, including lectures by M. Des Granges. There will be numerous excursions to the mountains and forests under the direction of the Department of Nature Study. The detailed calendar of the daily conferences will be announccd so that it will be possible to plan attendance for a portion or the entire session. The conferences will be opened by Dr. George D. Rosengarten, President of the American Chemical Society, and the presiding chairmen will be the members of the directing committee listed above and others. The general chairman will be Dr. H. E. Howe, Editor of I n d u s t r i a l and E n g i newing Chemistry. Detailed information, housing reservations, and a special bulletin may be obtained by writing to G. I,. Wendt, Director, Institute of Chemistry, State College, Pa. Nicotine Has Rival in Insecticide Field. Nicotine, thus far practically unrivalled as an insecticide against plant lice, may soon have a serious competitor in the field through the results of experiments carried on a t the U. S.Bureau of Entomology. An ail prepared from pyridine, which forms an essential part of nicotine, combined with sodium, has been found t o he poisonous t o plant lice. Like nicotine it destroys the lice without injuring the infested plants. Entomologists believe it possible that dipyridyl oil, as the new compound is called, ma). prove moreeffective thannicotine for the practical control of some injurious insects. Thus far the economic phase of large-scale production of the new insecticide has not been thoroughly gone into, but it is believed that it can he made as cheaply as nicotine. Pyridine is obtained from coal-tar distillation as a by-product and islargely wasted. The supply is great and the demand small so that it is fairly cheap. Sodium may also be obtained a t low prices. The cost of the new product should, therefore, not exceed the cost of nicotine. Entering into the field as a rival, i t may possibly bring down the price of nicotine. I t is difficult t o find chemicals possessing sufficient toxicity t o destroy plant lice and, a t the same time, not injure the plants. The bureau experimented with sixteen other organic compounds whose toxicity was inferior as compared to dipyridyl oil.Science Sewice
