=WALKER, JAMES. Organic Chemistry for Students of Medicine.= Illus. 6 x 9. cloth. 328 pp. =net, $2.50= =WALSH, J. J. The Chemistry of Mining and Mine Ventilation.= In Press. =WARNES, A. R. Coal Tar Distillation and Working Up of Tar Products.= 67 illustrations. 5-3/4 x 8-3/4. cloth. 197 pp. =net, $2.50= =WHITE, C. H. Methods in Metallurgical Analysis.= 106 illustrations. 5 x 7-1/2. cloth. 365 pp. =net, $2.50= =WILSON, E. J., and HEILBRON, I. M. Chemical Theory and Calculations.= An elementary text-book. Illus., 3 folding plates. 12mo. cloth. 145 pp. =net, $1.00= =WOOD, J. K. The Chemistry of Dyeing.= 5 x 7-1/2. cloth. 87 pp. (Van Nostrand’s Chemical Monographs.) =net, $0.75= =WORDEN, E. C. The Nitrocellulose Industry.= A compendium of the history, chemistry, manufacture, commercial application, and analysis of nitrates, acetates, and xanthates of cellulose as applied to the peaceful arts. With a chapter on gun cotton, smokeless powder and explosive cellulose nitrates. Illustrated. 8vo. cloth. Two volumes. 1239 pp. =net, $10.00= =—— Technology of Cellulose Esters.= A theoretical and practical treatise on the origin, history, chemistry, manufacture, technical application and analysis of the products of acylation and alkylation of normal and modified cellulose, including nitrocellulose, celluloid, pyroxylin, collodion, celloidin, gun-cotton, acetycellulose and viscose, as applied to technology, pharmacy, microscopy, medicine, photography and the warlike and peaceful arts. _In ten volumes._ 600 ill., 12 plates, containing upwards of 110,000 patent and literature references to the work of 12,000 different investigators. _An Exhaustive Treatise._ 4000 pp. Vol. VIII. =Carbohydrate Carboxylates= (=Cellulose Acetate=). Illustrated. 6-1/2 x 9-1/2. 515 pp. =net, $5.00= (Other _volumes_ to follow at short intervals.) =WREN, HENRY. Organometallic Compounds of Zinc and Magnesium.= 5 x 7-1/2. cloth. 108 pp. (Van Nostrand’s Chemical Monographs.) =net, $0.75=