insulations made with phenolic resins, shellac, gums, pitches, and similar materials. The fact that metal parts can be combined with Mycalex during the molding process means a tighter and stronger combination. As a rule, metal inserts cannot be imbedded in ceramic products during the process of manufacture. This is especially true of porcelain because of the considerable shrinkage and the high temperature which causes melting or slagging of metal parts. Not only has i t better electrical properties than porcelain, but i t is
Mycalex Parts with Metallic Inserts Molded in Place.
stronger mechanically except under compression. Although i t can be drilled, filed, sawed, polished, and similarly treated by usual machining methods, i t is necessary in some instances to use special tools since the wear when working with Mycalex is greater than when cutting metals. The new material has been recommended for use where the requirements demand an insulating material of high mechanical strength, dielectric strength and insulating resistance, low losses with high frequencies, heat resistance beyond the ordinary range of molded or sheet materials, and compact construction with metal inserts securely molded in place.
More Vaccinations Needed in France to Curb Smallpox. General alarm on the part of the health authorities is expressed over the falling offin the numberof smallpox vaccinations shown in the annual report for the year 1925 just in from all the departments. The decrease is in part accounted for by the lowered birth rate hut much of i t is imputed to general carelessnessand relaxation in carrying out vaccination regulations. The Vaccination Commission has called attention to the fact that the present centers of smallpox epidemics at Paris, Douai, Saint Etienne, and Valence originated in cases among Arabs recently disembarked from Algiers. It is strongly recommended that effective revaccination be required in all inhabitants of the French colonies and of the countries under the protectorate of France before they he allowed to enter themather country.-Science Seraice
