458 POPULAR SCIENCE MONTHLY. 



a decrease in attendance after the Christmas and April holidays. 

 These lessons were followed by five on elementary chemistry, by 

 Prof. L. M. Norton, of the Massachusetts Institute of Technology. 

 His subjects were as follows: First Principles of Chemistry; the 

 next, Chemistry of Air, Chemistry of Water, Chemistry of Com- 

 bustion, Chemistry of Metallic Elements. There were also five 

 on Practical Examination, with Simple Apparatus of the Physics and 

 Chemistry of Vegetable Physiology, by Professor Goodale, which 



LABORATORY OF THE BOSTON SOCIETY OF NATURAL HISTORY USED BY CLASSES OF THE 

 TEACHERS' SCHOOL OF SCIENCE. 



were divided as follows: (1) Vegetable Assimilation, the mode in 

 which plants prepare food for themselves and animals; (2) The 

 Kinds of Food Stored in Vegetable Organs, illustrations of the 

 starches, sugars, oils, and albuminoidal matters; (3) How Food is 

 used by Plants and Animals in a Formation of New Parts, mechan- 

 ics of growth ; (4) How Food is Used in Work of all 3inds by Differ- 

 ent Organisms; (5) Adaptations of Organisms to Extremes of Heat 

 and Light, chiefly with respect to geographical distribution. This 

 session was concluded with a series of five lessons on Chemical Prin- 

 ciples illustrated by Common Minerals, by Professor Crosby. 



At the beginning of this season there was the usual large attend- 

 ance, with teachers from thirty towns, but the number was slowly 

 reduced. It was evident to the curator that the decline in attend- 

 ance was not due to the subjects nor the mode in which they were 



