ii Agricultural Science Series Farm Horticulture-Hood New Editi met the need for which it was created, is That "Farm Horticulture shown by its popularity which has exhausted the first edition in a little over a year. It is especially gratifying that this demand has come largely from agri cultural high schools and colleges, thus indicating the permanent worth of the book and its establishment in the educational system of the country. Primarily an elementary text, the book is so arranged and developed as to meet the needs both of the student and those practicing Horticulture. Many teachers of Elementary Agriculture and Horticulture have found it suitable a a text and it is hoped and believed that they will be even more pleased with the revised edition. New material has been incorporated wherever it would add to the value of the work or increase its utility. A few chapters did not treat their subjects as fully as they merited but these have now beer enlarged so as to make them better serve their purpose. The subject matte has also been rearranged to conform more closely to the usual method o teaching Horticulture. To the farmer or the city suburban family interested in Horticulture, i will be a guide to the successful growing of their plants. It gives information on the most important facts and subjects in Horticulture, particularly relativ to those practices which many people desire but which heretofore could not b found in any single text. The diagrams and plans for gardens of varying size are most practical and helpful as are the chapters on The Seed, Cultivation and Village, Budding and Grafting, Harvesting and Marketing (including Pack ing), Pests and how to combat them, also the special chapters devoted to th individual fruits and Beautifying the Home Grounds. The methods advanced throughout the book are those which lead to practical success in this field. Cloth, $2.75, ne By GEORGE W. HOOD, M.Sc., Associate Professor of Horticulture, University of Nebrask 12m0, 354 pages, with 144 illustrations. Agricultural Entomology By HERBERT OSBORN, B.SC., M.Sc., Professor Vegetable Growing By HERBERT OSBORN, B.Sc., M.Sc., Professor The Chemistry of Agriculture 121 Live Stock Judging and Selecti Poultry Production By WILLIAM A. LIPPINCOTT, A.B., B.S., Professor of Poultry Husbandry, Kansas Sta 706-10 Sansom St. LEA & FEBIGER Philadel D A Series of Talks on Hydrogen-ion Measurements The Potentiometer in H-ion Determinations A measuring instrument is no more accurate than its standardization. A Potentiometer is an instrument for measuring potential differences. It depends for its accuracy on a standard cadmium cell-the universally accepted standard of electromotive force-and on the constancy of the electrical resistance in its measuring circuit. Manganin resistance wire, used in Leeds & Northrup potentiometers, is extremely dependable for its constancy. With a Potentiometer, measurements are easily and quickly made, even by the experimenter who has had little experience. The user can always, in a few moments, satisfy himself that his measurements are trustworthy, by checking his measurements against a standard cell. The standard cell, with ordinary use, lasts indefinitely. The Leeds & Northrup Type K Potentiometer, because of its excellence of design and construction, has made a reputation for itself in hundreds of laboratories. Scientific literature shows that the large majority of recent researches involving accurate hydrogen-ion determinations have been made with the aid of a Leeds & Northrup Potentiometer. Our Catalogue $75 on "Electrometric Methods and Apparatus for Determining Hydrogen-ion Concentrations" contains many pages of useful information on this subject. It will be sent you, if you want it, with our compliments. Leeds&Northrup Company 4901 Stenton Avenue Electrical Measuring Instruments Philadelphia, Pa. DIFCO RARE SUGARS and OTHER FINE CHEMICALS "DIFCO" STANDARDIZED Being the first manufacturing firm in the Unit States to make and advertise extensively rare sugars, we have steadily added to the line, and our list now comprises the following: OTHER CHEMICALS Inulin Mannite Dextrin Galactose Invert Sugar Lactose Levulose (Fructose) Maltose Blood Serum, Dry Acid Potasium Phthalate Decolorizing Carbon Tyrosine Beef Extract Mannose Melezitose Raffinose Rhamnose Fibrin Saccharose (Sucrose) Gelatin Trehalose Xylose SPECIFY "DIFCO". WE INVITE COMPARISON Descriptive literature and prices upon request Carried in stock by the principal dealers in Scientific Supplies Digestive Ferments Company Detroit, Michigan, U. S. A. Repeated object lessons have demonstrated that nearly all progress in science has resulted in important advances in industry G-E Research Laboratory Schenectady, N. Y. Among the many products developed by the General For further information address Supply Department, Schenectady Office. General Electric General Office Company |