There are two kinds of condensed milk sold in cans. These are known as condensed milk "with" and "without" sugar. In the preparation of the first-mentioned kind a large amount of cane sugar is added to condensed milk, and this acting as a preservative renders the preparation and successful handling of this article of food comparatively easy. On the other hand, condensed milk to which sugar has not been added is very liable to decomposition, and great care must be used in its preparation. The writer has seen several cases of severe poisoning that have resulted from decomposed canned milk. Any of the galactotoxicons (milk poisons) may be formed in this milk. In these instances the cans were "blown," both ends being convex. One of the most important sanitary questions in which we are concerned to-day is that pertaining to the subject of canned meats. It is undoubtedly true that unscrupulous manufacturers are putting upon the market articles of this kind of food which no decent man knowingly would eat, and which are undoubtedly harmful to all. The knowledge gained by investigations in chemical and bacteriological science have enabled the unscrupulous to take putrid liver and other disgusting substances and present them in such a form that the most fastidious palate would not recognize their origin. In this way the flesh from diseased animals and that which has undergone putrefactive changes may be doctored up and sold as reputable articles of diet. The writer does not believe that this practice is largely resorted to in this country, but that questionable preservatives have been used to some extent has been amply demonstrated by the testimony of the manufacturers of these articles themselves, given before the Senate committee now investigating the question of food and food adulterations. It is certainly true that most of the adulterations used in our foods are not injurious to health, but are fraudulent in a pecuniary sense; but when the flesh of diseased animals and substances which have undergone putrefactive decomposition can be doctored up and preserved by the addition of such agents as formaldehyde, it is time that the public should demand some restrictive measures. WIRELESS TELEGRAPHY. BY PROF. JOHN TROWBRIDGE, DIRECTOR OF JEFFERSON PHYSICAL LABORATORY, HARVARD UNIVERSITY. I never visit the historical collection of physical apparatus in the physical laboratory of Harvard University without a sense of wonderment at the marvelous use that has been made of old and antiquated pieces of apparatus which were once considered electrical toys. There can be seen the first batteries, the model of dynamo machines, and the electric motor. Such a collection is in a way a Westminster Abbey--dead mechanisms born to new uses and a great future.