640 POPULAR SCIENCE MONTHLY. 



culosis are removed, even if they do not admit that intestinal trou- 

 bles are thus avoided. 



There can be little doubt that the method would be successful 

 in our own cities, but its success would depend upon the price at 

 which the milk is sold. If the Pasteurized milk is sold for a price 

 much higher than ordinary milk it will not be a commercial success, 

 for the vast majority of people prefer to save the one or two cents 

 per quart, and run the rather slight risk of trouble from the milk. 

 If it can be sold in our cities, as in Copenhagen, for the same price 

 or a price only slightly higher than that of ordinary milk, it is hardly 

 doubtful that it would soon come into favor, for who would not 

 prefer milk that is safe from disease germs if the price is the 

 same? Already there are a few attempts in this direction in some 

 of our cities, but as yet they are only in the beginning stage. 

 Whether they will develop to a wide extent depends probably 

 almost wholly upon the price at which the milk can be sold. 



It would appear, then, that this method of Pasteurization by a 

 central company offers the most hopeful solution of this feature of 

 the problem which is growing with the growth of cities. The milk 

 companies could probably arrange, without great expense, such a 

 plan of Pasteurizing large amounts of milk. This only emphasizes 

 the conclusion, already reached, that the most hopeful method of 

 dealing with the problem in our cities is through properly organized 

 companies that can handle milk on a large scale, and will do it con- 

 scientiously, and not wholly from the standpoint of money-making. 



TEACHERS' SCHOOL OF SCIENCE. 



BY FKANCES ZIENGIEBEL. 

 [Concluded. ] 



1 PARALLEL in time with the course in historical geology or pa- 

 -*- leontology was that in botany, under the leadership of Dr. 

 Robert W. Greenleaf, a Boston physician, who in his student days 

 had assisted Dr. Goodale and was at the time of giving these lessons 

 Professor of Botany and Materia Medica at the Massachusetts Col- 

 lege of Pharmacy. A growing interest in the study of botany in the 

 schools, and Dr. Greenleaf's exceptional ability as a teacher, made 

 the attendance at this class very large. After an hour's lecture the 

 instructor and two assistants directed the observation of the speci- 

 mens by the students, who were required to make sketches of the 

 objects studied. The first set of lessons was similar to that given 

 in the school by Dr. Goodale several years before, and was of a 



