POPULAR SCIENCE MONTHLY.
recognition to sciences other than those commonly called natural and exact, the conditions that prompted the establishment in England of a special Academy may lead to a similar undertaking in the United States. The national societies devoted to history, economics, philology, archeology and the like fill most of the important functions that were formerly exercised by a national academy, but there appears to be as much reason for the students of these sciences to unite in a national academy as there is in the case of the natural sciences. There seems also reason to suppose that the societies referred to will form some basis of cooperation as the natural sciences have done by uniting in the American Association. Whether all the sciences should unite in one national academy and in one national association or whether they should divide into two separate groups is certainly a question of considerable importance.
THE GERMICIDAL ACTION OF THE ORGANIC PEROXIDES.
Drs. F. G. Novy and P. C. Freer, of the University of Michigan, presented at the Chicago meeting of the American Society of Bacteriologists an important paper that has been extensively, but not very accurately, reported in the daily papers. The authors stated that their investigation was begun with the object of finding the correct explanation of the action of metals and of sunlight upon bacteria. Certain metals, such as gold and copper, exert a marked inhibiting and even germicidal effect upon some bacteria, but the interpretation of the results has not been wholly satisfactory. The fact that various surfaces, such as metals and fabrics, exert a marked effect upon the formation of benzoyl acetyl peroxide was established by the authors and served as a basis for the Adew that metals act upon bacteria by giving rise to energetic peroxides, which, of necessity, must be more active than ordinary peroxides. The action of sunlight has been ascribed by different workers to hydrogen peroxide, but the destructive action observed is greater than that which can be credited to this body. In order to substantiate the theory of the authors regarding the action of metals and of sunlight, it was deemed necessary to investigate the action of a number of known organic peroxides. The results show that some of these bodies, such as aceton peroxide and dibenzoyl peroxide, are wholly inert. On the other hand, solutions of diacetyl, benzoyl acetyl, and of benzoyl hydrogen peroxides, and of phthalmonoperacid, exert pronounced and even remarkable germicidal properties. With reference to diacetyl peroxides and benzoyl acetyl peroxide, it was shown that the bodies themselves are chemically and bacterially inert, but on contact with water they undergo hydrolysis and give rise to the extremely energetic acetyl hydrogen and benzoyl hydrogen peroxides. A solution of these peroxides (1:3,000) is capable of destroying all pathogenic bacteria. Cholera and typhoid germs added to tap water are promptly destroyed by the addition of one part of peroxide to 100,000 parts of water. The authors point out the probable value of these peroxides in the prevention and cure of these and allied diseases. The destruction of bacteria in the mouth and saliva takes place with extraordinary rapidity and the reagents have shown themselves useful in diseases of the mouth. The powerful effects of the organic peroxides is not explainable as due to nascent oxygen, since a solution of hydrogen peroxide, which will produce equal germicidal action, contains one or even two hundred times as much nascent oxygen. The authors incline to the belief that the acetyl and benzoyl ions are the active agents.
TWILIGHT IN THE TROPICS.
Professor S. I. Bailey, of the Harvard College Observatory, presented a