VOL. 6, No. 5
RECENTBOOKS
The Sulphoaluminates of Calcium. W. , R. H. LBRCE, F. W. A S ~ O NAND Bocuz,, Bureau of SLendnrds, Research Paper No. 54, Department of Commerce. U. S. Government Printing Office,Washington, D. C., 1929. 17 pp. 14.5 X 23 cm. 80.10. "Two calcium sulfoaluminates have been prepared and their compositions and optical characteristics determined. One of these, having the composition 3CaO.Al~Oa.3CaS0~~31H~0, is relatively stable in aqueous solutions hut is decomposed by solutions of magnesium salts and of carbonates. The other, having the composition 3CaO.AlaOrCaSOI.12Hs0, is relatively unstable except in high concentration of hydraxyl ion. I t is readily converted t o the high sulfate form in aqueous solutions but is decomposed by magnesium salts and carbonates. I n sulfate solutions the high form may he produced, but in the presence of a slight excess of magnesium salts or carbonates neither of the sulfoaluminates can continue to exist. I n these cases the less soluble magnesium hydroxide and calcium carbonate, respectively, are formed." M. W. G. Third Report of Commission on Medical Education. A. LAWRENCE LOWELL, Chairman. Office, Director of Study, 215 Whitney Avenue, New Haven. Conn. October, 1928. 70 pp. 14.5 X 23 cm. This report is the third hut not the final of the commission on medical education. The commission has endeavored t o present what it believes t o be the most important principles that should be emphasized in medical training. The first part of the report is a statement of these principles and the second part is a brief amplification and discussion of them. The headings of the chapters in each part are: (1) Pre-Medical Education, (2) Teaching in the Medical Sciences,
1007
(3) Teaching in Clinical Medicine, (4) General Considerations. The appendix includes information (1) The Growth of the relative to: Student Body in Secondary Schwls and Colleges, (2) Applications for Admission to Medical Schools, (3) Organization of Clinical Teaching, (4) The Teaching of the Practice of Preventive Medicine in M. W. G. the Individual.
