VOL.7. No. 7
PRINTING PROCESSES.
1641
I11
inks, t h e i r particular properties, uses, etc. It also contains bibliography on ink and printing processes in general.
a valuable
Additional References Additional
works which can be read with a great deal of profit are:
SIGMUND LBnmn. "Ink Manufacture," Scott. Greenwood & Son, London, 1914. DAVID N. CARVALHO. "Forty Centuries of Ink," Banks Law Pub. Co., New York City. 1904. NORMAN UNDERWOOD, "Chemistry and Technology of Printing Inks," D. Van Nostrand Co.. New York City. 1915. C. A. MITCHELLAND T. C. H E P W O R ~"Inks. , Their Composition and Manufacture," Chas. Griffin & Co., London, 1924.
Bacteriophage Not Organism, Says Bacteriologist. "A systematic study of the properties of bacteriophage failed t o substantiate its living nature;' stated Dr. J. Bronfenbrenner, professor of bacteriology a t the Washington University School of Medicine, in an address before the recent meeting a t Ames, Iowa, of the Society of American Bactedoloaists. The evidence seems to indicate that the bacterio~haze - - is an inanimate chemical product of bacterial metabolism, having no cell-dissolving properties of its own. Bacteriapha~e germ-killer,heina . . has been hailed as a most patent . - made itself from germs, hut ever since its discovery by Dr. F. d'HereUe it has been a suhject of scientific controversy. "It seems to exhibit a stimulating cRect a n homdogous or closely related bacterial ~pecics. As a result, the rate of intracellular metabolism is abnormally increased with a consequent increase in osmotic pressure within {he ceU, and if water is available in the surrounding medium, bacteria take i t up, swell, and Snally burst." The activity of the phage in suppressing the effects on animal tissue of a definite chemicals. The germ without harming the tissue was compared with activity of cephage was active a t a much wider range of dilutions than any of the five chemicals, mercuric chloride, phenol, formalin, tincture of iodine and chloramine, John E. Walker of the research laboratories of E. R. Squibb and Sans reported. This phage was active a t dilutions ranging from full strength t o a dilution of 1 to 512, while the nearest chemical, mercuric chloride, could only be diluted t o one-sixteenth of the strength causing tissue destruction and still be active.-Science SerJicc Philosophy Needed to Solve Teachers Problems. Educators should not be fetish worshipers, faithfully applying, like chams, the bits of scientific knowledge discovered for their use. They should link philosophy t o science. Thus Dr. Truman L. Kelley, vice-president of the section of educators a t the Des Moines meeting of the American Association for the Advancement of Science, emphasized the great need for a finer philosophical attitude toward education as science brings new tools to the hands of teachers. Dr. Kelly discussed particularly the danger of depending arbitrarily on psychological tests, now widely used in schaols to appraise the abilities and progress of young students. The test score is never a substitute for judgment: i t is merely an aid in making judgments, he emphasized. The r6Ie of science is t o furnish permanent solutions t o 'specific problems. Philosophy is needed to fit this knowledge into the immediate situations which the teacher must face, for in such situations there are always many factors not accounted for by scientific investigations.-Science Service
