2308 TOURNAL OF CHEMICAL EDUCATION

which the student will have to unlearn later, and to a certain extent the authors attempt to correct themselves on pages 232 and 233. The whole treatment would he considerably improved if the authors would point out that the mobili- t ~ s of the ions change with the ionic concentration, making it impossible to determine the degree of ionization of strong electrolytes from the simple h/h . ratio.

On page 239 the authors write "With the development of the theory of electro- lytic dissociation, it was soon realized that the fundamental property of an acid is its ability to dissociate in aqueous

solution to give a larger concentration of hydrogen ions than that which exists in pure water alone." A more general. more fundamental and more fruitful definition is that an acid is a substance which gives up a proton.

I n justice to the authors it should he said that the same faults exist in most of the other introductory texts on theo- retical chemistry. The reviewer recom- mends this book and would like to see i t used as a basis for a second course in chemistry.

MARTIN KrLPAmIcK. Jn. UNWsaslru or PBNNSYLY*NI*

PHILADELPlr*, PBNN*.

Instrument Tests Tender Steaks. An instrument made from an ordinary auto- mobile tire pressure-sauce for estimatinc the tenderness of meat, was described a t the . . . Ainerican Chemical Society meeting by Donald K Tresslcr of Gloucester, Massachusetts, and William T. Murray. Another instrument for the same purpose is a modified form - ~

of a standard laboratory penetrometer.-Science Service

Vegetarians Live More Slowly. A study made on thirty long-time vegetarians shows that their basal metabolism is from ten to fifteen per cent below the average of habitual meat-eaters. Short-time vegetarianism does not seem to have such effects, said Prof. Glen Wakeham. of the University of Colorado, and Louis 0. Hansom a t the meeting of the American Chemical Society.-Science Scrvice

Tougher Germs to Test Disinfectants. Standards for staphylococcus germs with which to test the strength of disinfectants have been too lax, said Dr. George F. Reddish, of St. Louis, Mo., a t the meeting of the American Chemical Society. Weak germs will he excluded from the new standards incorporated in the forthcoming bulletin of the U. S. Food and Drug Administration on methods of testing disinfectants and anti- septics.-Science Service

Refrigerators Heat California Building. Refrigeration in sunny California now provides for winter heat. The same system that cools air in summer has been made to warm things up when the snow starts thickening on the mountain peaks.

In a new office building, erected for an electrical company in Los Angeles, suitable apparatus has been installed. As in an ordinary refrigeration system, the refrigerant is vaporized by absorbing heat from a container of water, which i t cools. When it con- denses it heats up the water of a second container.

Air is passed over the cooled water to make the building comfortable in summer. During the winter months, the water from the condenser is circulated through a tubular device which raises the building's air supply to a temperature of 80 degrees Fahrenheit. To provide for an outside source of energy, necessary in the operation of the system, the - ~

atmosphere is used. Towers on the roof of the building force an air draft which gives the water in the two containers temperatures from which the refrigeration system can operate.-Science Service