December 9, 1910] 



SCIENCE 



823 



services which Ehrlich and his pupils have 

 rendered humanity. Such vast progress 

 has already been achieved in chemotherapy 

 that it will necessarily be only a matter of 

 a short time when it will become possible 

 to definitely arrest the ravages of such 

 terrible diseases as syphilis, recurrent 

 fever and sleeping sickness. Perhaps 

 cancer, the cause of which has been as- 

 cribed by some investigators to organisms 

 resembling the spirochete of syphilis, will 

 also be found amenable to chemotherapy. 



This marvelous success of modern ther- 

 apy is, in a large measure, due to synthetic 

 chemistry, which in the past has already 

 rendered invaluable assistance to the med- 

 ical practitioner by furnishing him such 

 efficient remedies as antipyrin, phenacetin, 

 trional, veronal, hexamethj'leu-tetramin, 

 and aspirin. How, in the light of these 

 positive advances, can we explain the atti- 

 tude of those few who are still opposed to 

 progress in medicine to which our science 

 has chiefly contributed. A few years ago 

 when we celebrated the birth of synthetic 

 chemistry by commemorating the fiftieth 

 anniversary of Perkin's discovery of the 

 first anilin color, one of these obstruction- 

 ists stated in a discussion that he believed 

 very few useful drugs had been put out 

 by the manufacturing chemists, and that 

 we should be better off if Perkin had never 

 discovered coal-tar products. The anilin 

 colors were cheap and gaudy and did not 

 last, and the coal-tar drugs were in the 

 same class. He believed that the good that 

 coal-tar products had done was being neu-- 

 tralized by the harm. 



Let us hope that after a closer study of 

 the subject this short-sighted man has 

 meanwhile learned that he is wrong in 

 eveiy particular; for there exist coal-tar 

 dyes which are ever so much faster than any 

 coloring matter supplied by nature, and 

 coal-tar derivatives in the hands of com- 



petent physicians do as little harm as any 

 active drug in the pharmacopoeia. 



In fact, it is no exaggeration to say that 

 there is scarcely a department in medicine 

 that has not directly benefited through the 

 discovery of the coal-tar products and es- 

 pecially of the anilin dyes. It has provided 

 the anatomist and pathologist with the 

 means of staining various tissues and thus 

 of studying not only their normal structure 

 but the alterations caused by disease. It is 

 the foundation upon which has been built 

 the modern science of bacteriology, ena- 

 bling the investigator in this field to dis- 

 tinguish between the different disease or- 

 ganisms and to determine their presence 

 by various tests, and now it bids fair to 

 equip the physician with the most potent 

 weapons in the warfare against disease. 



H. Schweitzer 

 New Yobk City 



TBE ISt^TRUCTION OF LARGE VNIVERSITT 

 CLASSES 



The great increase of students in universi- 

 ties has brought up the problem of instruct- 

 ing students efficiently in large classes. The 

 problem presents so many difficulties, and is 

 one that so many instructors are wrestling 

 with, that we have thought that it might be 

 of value to describe the methods of handling 

 large classes in a physics course in which 

 there are lectures, recitations and laboratory 

 exercises. 



In this course there are registered about 

 400 students. Two lectures are given each 

 week together with one quiz and two two-hour 

 laboratory periods. The course continues 

 throughout the college year, and covers the 

 usual range of topics of a course in general 

 physics. The lectures are given on Monday 

 and Wednesday mornings at nine o'clock and 

 repeated at eleven o'clock on the same days, 

 the class being divided equally for the two 

 periods. Experience has shown that 200 is a 

 maximum number of students for experi- 

 mental lectures, even with a good lecture 



