April 7, 1922] 



SCIENCE 



357 



elude general chemistry and qualitative analysis 

 in one intensive course of two laboratory 

 periods, two quiz periods, and two lectures per 

 week throughout the year. It has thus been 

 possible to minimize the usual break between 

 these subjects and to develop systematically 

 from the general principles of chemistry to 

 their application in the problems of analysis. 

 In the laboratory manual, written by Professor 

 W. C. Bray with the assistance of Dr. W. M. 

 Latimer, the effort has been to stimulate the 

 student, through proper experiments; first, to 

 gain a working conception of the atomic the- 

 ory, the molecular theory and the behavior of 

 gases. There follows next, a study of acids and 

 bases and of titration, in order to develop and 

 apply the idea of concentration. A further 

 study of acids, bases and salts leads to the 

 ionic theory. In this connection we have not 

 considered it necessary to discuss an element 

 at length before studying one of its compounds. 

 Acetic acid, for example, is a quite familiar 

 substance, whose acid properties may be in- 

 vestigated before studying organic chemistry, 

 and it is not necessary to discuss sulfur, sulfur 

 dioxide and the manufacture of sulfuric acid 

 in order to do some laboratory work with the 

 acid. There follow assignments on strong and 

 weak acids and bases and the uses of indica- 

 tors to measure the concentration of hydrogen 

 ion; rapid reversible reactions and equilibrium; 

 the reversibility of neutralization reactions, or 

 hydrolysis; the jsroperties of sodium, potas- 

 sium and ammonium ions and the tests for 

 sulfate and nitrate ions; the chemistry of 

 calcium ion, developing solubility equilibria and 

 the transformation and solution of precipi- 

 tates; carbonic acid, carbonate and bicarbon- 

 ate ions; the salts of copper, sulfur and zinc, 

 which prepare the way for the study of com- 

 plex ions, amphoteric hydroxides and the im- 

 portant reactions utilized in qualitative anal- 

 ysis. 



Unknown solutions of increasing difficulty 

 are introduced during this period, but more 

 emphasis is placed upon the student devising 

 methods of analysis than upon committing to 

 memory and using the orthodox schemes, which 

 few chemists ever use in actual practice with- 



out appropriate short-cut modifications. Oxida- 

 tion and reduction reactions and electric cells 

 aj-e next introduced, followed by a study of 

 ions whose separations involve oxidation and 

 reduction. 



The effort is made constantly to throw the 

 student upon his own responsibility, especially 

 in observing accurately and in drawing general 

 conclusions from his experiments. There are 

 numerous questions calling upon him to pre- 

 dict results of untried experiments. 



The lecture work is organized to supplement 

 closely the laboratory work and to contribute 

 an element of stimulus and inspiration. The 

 topics in the early part of the course are taken 

 up in much the same order. When acids, bases 

 and salts are introduced in the laboratory, the 

 lectures take up the alkali metals followed by 

 the alkaline earth metals. The chemistry of 

 the metals is so much simpler than that of the 

 non-metals that we have been more than satis- 

 fied by our abandonment of the usual order of 

 presentation in which the halogens are intro- 

 duced early in the course. An intensive study 

 of the periodic system and its use in predict- 

 ing and correlating not only physical proper- 

 ties but chemical characteristics as well, con- 

 tinues throughout the year with necessary in- 

 terruptions from time to time by other topics. 



A reference book has been written for the 

 course in which the aim has been to present 

 clearly and briefly the principles of chemistrj'. 

 The topics have been aiTanged in convenient 

 order for reference rather than as jn the lec- 

 tm-es. The i^rogi-am of the lectures can thus 

 readily be altered from year to year to ti-y ex- 

 periments of instruction, and making it easier 

 to avoid tlie stagnation so fatal to even the best 

 of cou.rses. 



But though general principles are emphasized 

 in the teaching, we feel that the final test should 

 not be the statement of the theories but their 

 application. In our examinations, therefore, 

 we usually say little about theories and prin- 

 ciples, asking the student rather now to pre- 

 pare one salt from another; how to accelerate 

 or retard given reactions; how to shift certain 

 equilibria; how to dissolve various precipitates; 

 whether he would expect a given acid to be 



