May 5, 1916] 



SCIENCE 



625 



tematic and orderly, while the laboratory 

 work is necessarily more or less topical, the 

 pupil thinks the lectures are the real kernel 

 of the course. Yet, in point of fact, the 

 real contact with the subject takes place 

 in the laboratory, and it is better therefore 

 to make the student feel that the laboratory 

 work is the principal feature of the course, 

 and that the class-room work is simply a 

 discussion and adjustment of what he has 

 learned in the laboratory and at home. 

 Individual observation and reasoning from 

 observation, can thus receive that strong 

 emphasis which they deserve, but in a lec- 

 ture can never receive. Naturally, every 

 week each student must begin with the ex- 

 periments for that week, since he can not 

 otherwise prepare himself for the class 

 meetings. 



Finally, many chemists admit that they 

 learned little chemistry from the first lec- 

 ture course, but insist that the personality 

 and point of view of the lecturer — not only 

 in matters chemical, but in respects quite 

 remote from that science — exercised a pro- 

 found influence upon their own point of 

 view and their subsequent attitude towards 

 life. In reply, it need only be pointed out 

 that, in the free interchange of thought 

 which is a necessary part of the method 

 suggested, the opportunity for the person- 

 ality of the instructor to assert itself is even 

 freer than it ever can be in a lecture, and 

 that the digressions, if they are such, since 

 they will usually be suggested by reactions 

 shown by the students themselves, will be 

 much more likely to strike some target 

 effectively and forcefully than will the 

 random shots of a lecturer, who knows only 

 what is in his own mind, and nothing of 

 what is in the mind of the listener. 



Improved Laboratory Facilities. — The 

 mechanical equipment of a chemical labo- 

 ratory is an important efSciency factor in 

 the training of chemists. There is perhaps 



no department in the college or university 

 where the ratio of results achieved to time 

 spent is so small. This is particularly true 

 of the quantitative and organic labora- 

 tories, although it is conspicuous in all 

 branches of the science. 



For example, the evaporation of a solu- 

 tion on a steam bath may take five or six 

 hours. The temperature of the liquid may 

 never greatly exceed 90°. A vigorous at- 

 tempt is made to train the student to carry 

 on several operations simultaneously, but 

 four or five months elapse before he learns 

 to do this effectively. A plate covered with 

 shot and heated with steam under pressure, 

 one at each working place, will easily give 

 a temperature of 130°. The time required 

 for the evaporation will become a mere 

 fraction of that required with an ordinary 

 steam bath, and the saving of time will 

 begin on the first day, instead of being 

 postponed until months of training have 

 brought about the same result by another 

 method. The cost of fuel will also be less. 

 When the dissolved substance is a very 

 soluble one, the vapor pressure of the solv- 

 ent becomes rapidly smaller as evaporation 

 proceeds, and soon the steam escaping from 

 a bath gives to the air a partial pressure 

 of water vapor equal to the vapor pressure 

 of the solution, and evaporation ceases. 

 With the steam confined in the plate, so 

 that saturation of the air is avoided, the 

 evaporation will proceed much further 

 without interruption. A tube connected 

 with a vacuum system, provided on all 

 desks, will remove the vapor, and will facili- 

 tate further evaporation beyond this point 

 to a surprising degree. Desk ventilation 

 is of course required when the steam plate 

 is used. 



Ventilation at each working place, as it 

 has been installed in the new laboratory 

 here, also permits much saving of time. 

 Hoods take the student away from his desk 



