pared variety, but that the a~semblyof the apparatus shall form an important feature of the exercise. The reviewer feels that these views should command eonsideration in physieochemieal laboratories here. The root-evil of brief threchovr psriods on one or two days per week. as is mmmon in this country, is that if leads to exceaive standardisation of exercises. prior preparation of apparatus by instructors and lo. of real experience by the student. The author's motto is Mullurn non muan. There are thirty-four exercises in the book in four sections: (11 onthe stoiehiometrgofpure substances and solutions; (2) on chemical dynamics; (3) on thermoehemistry and: (41 on electmehemistry. They are the dassieal exerei~esin physical chemistry with the possible exception of the measurement or dieleeuie constants d media by the capacity method. T h e are already English texts which cover these exercises as thoroughly as does the presentation in this book. o n e wonders whether the time is not ripe, in view of the tremendous accretions to physical chemistry since t h e molecttl~rweight-dilute rolutioo ern of the ruhjcr,, for a thor",,*h rrviion and cxtension of the courie work io p r ~ r t a c d~ h y r i c ehemirtry. ~l
Physiw Experiment Sheets. WILL^^^ B. Nsrson, M.S..Head of Department of Physic81 Seienecr. Manual Training High School. Brwklyn, N. Y. Globe Book Co.. New York. 1925. 128 PP.. bound. 26 X 20 em. $0.80. The sixty experiments emtaincd in this book are divided: 9 in hydrostatics, 15 in mechanics. 2 in magnetism. 6 in electricity. 8 ia electromagnetism, and 9 in heat. Of these, 88 require
the taking of quantitative data, the remaining 22 being qualitative.
There experiments are of the "stoek" type for an elementary high-school murse, containing: in hydrontaticr, experiments on specific gravity and liquid dirplaeement; in meehaoies, on parallel and concumnt forece, moment., center of gravity, friction. simple machines, and the vibration of a pendulum; in round, on beats and the vibration of a tuning fork; in light, on reflection from plane mirrors, internal reflection, refraetioo, and lenses; in magnetism, on magnetic fieldnof bar magnets; in cleetrieity, on cells. Ohm's law, Wheatstone Bridge, and chemieal action of a current; in electromagnetism, on the magnetic field about a conductor, and its applications t o the e1eetro. magnet, electric bell, motor, telepraph, telephone receiver, and eleetramagnetie induction; in heat, on thermometer sealen. linear expansion, specific heat, heats of fusion and vaporization, evaporation, and humidity. "In preparing these experiments the attempt has been made to provide t h e pupil with directions which he will be capable of understanding with n minimum of assistance from hi3 teacher." The inntructions are confined to one-half of each page, together with the table of data for the student's use. The other half of the page ir intended for diagrams (two pages of whieh are given as models) and answers to questions interq,erred throughout the inotmction~. To each experiment are attached questions to be answered as a eonelusion. A page of reference tables for specific gravities, specific heats. coefficient$of linear expansion, and humidity data is appended. The experiment sheets arc bound in book form with stiff covers maLing a permanent laboratory record. C. G. Ercn~m
Pottery Clay Aids Cholera Cure. Kaolin, a constituent of porcelain and toilet powder, is a beneficial remedy for Asiatic cholera. This feldspar clay. named far the Rao-Ling hills of China, has been used for centuries in that country not only in the manufacture uf porcelain but by pllysnans for fever3 and intestinal disorders. Toward the end of the n~neteenlhwntnry J u l u Stumpf of Wurzberg employed i t externally for septic wounds and ulcers and internally for cholera. But its modern medical applications with this exception appear t o have been confined, according t o editorial comment in the Journal of the American Medical Association, t o use as a atering material, a base for poultices, and dusting powder for wounds. Recent research puts these early uses, however, on sound scientific basis. It has been found t h a t though i t is not a n antiseptic agent, in fluid media if kept in motion it will carry down large numbers of bacteria. Thirty t o sixty grams daily, it was ascertained, will change materially the reaction of the intestinal contents. Medical workers in this field are now using kaolin very successfully not only for Asiatic cholera but bacillary dysentery and other acute intestinal disturbances as well.-Science Service
