234 



SCIENCE. 



[N. S. Vol. I. No. 9. 



evergreen shrubs out of doors or eveu 

 bought in the markets, as celery, cabbage, 

 etc. Roots may likewise come from the 

 markets, stems and buds abundantly from 

 the trees out of doors, and towards spring 

 the latter may be forced to open in warm 

 rooms. Far too little use is made of these 

 easily obtained materials. By the time the 

 vegetative organs have been studied the 

 first Apetalfe will be in bloom, and if the 

 students have been properly taught to use 

 eyes and hands the Apetalte will present 

 no difficulties ; later come other wild flowers, 

 and all is easy. 



Allow me, in conclusion, to sum up the 

 points of this paper. In the laboratory 

 teaching of large classes, the first essential 

 is a recognition of the fact that nothing can 

 replace individualism in teaching and that 

 a sufficient number of assistants should be 

 emploj^ed. These assistants must be in- 

 tending teachers, given some pedagogic in- 

 struction, supplied with a uniform plan of 

 work, but left very free in the details of their 

 modes of reaching the students. Classes 

 should be divided into sections with fixed 

 hours and containing not more than thirtj^ 

 men, over each of which one assistant has 

 entire charge until the end of the term. 

 As an aid to uniformity of plan and to 

 answer the innumerable legitimate ques- 

 tions which arise in laboratory work, as 

 well as to supply technical nomenclature, 

 weekly printed guides, fitted to the exact 

 work being done, should be supplied to 

 each student. Lectures and laboratory 

 work should be kept together and follow 

 such a course that the vegetative organs 

 upon which material is at all times avail- 

 able should be studied in the winter, and 

 the reproductive organs in the spring or 

 summer. 



So much for a general plan ; each teacher 

 must vary it in adaptation to his own 

 needs. W. F. Ganong. 



Smith College. 



MAGNETISM AND THE WEATHER. 

 Much time has been devoted to the study 

 of magnetic and meteorologic observations 

 with the hope of establishing a definite con- 

 nection between the two. The results thus 

 far have been almost entirely negative, al- 

 though a connection has been found with 

 auroras, and the diurnal range of air pres- 

 sure is now believed to be a thermo-electric 

 phenomenon, alUed to the diurnal range in 

 the swings of the magnetic needle. There 

 are certain well established facts that have 

 been ascertained regarding magnetism that 

 almost always stand at the base of all such 

 investigations, although it is admitted that 

 magnetic phenomena are extremely com- 

 plex, and those of the weather are far 

 moi'e so. 



1. The three principal magnetic con- 

 ditions or fluctuations are as follows : (a) 

 The diurnal change due to some combined 

 solar and terrestrial action, (b) Magnetic 

 storms, which are peculiar and sharp dis- 

 turbances, generallj^ originating in the sun. 

 These often occur at thi-ee or four successive 

 rotations of the sun . 



(c.) A gradual change in magnetism 

 from one day to the next. These are quite 

 singular, and have been studied more than 

 any other conditions in the hope of establish- 

 ing some relation with our weather. 



2. In studies of magnetism strenuous and 

 long continued efforts have been made to 

 establish a regular recurring period depend- 

 ing upon the rotation of the sun. It is 

 easy to see that if there were such regular 

 period its discoverj^ would be of the pro- 

 foundest significance. The results of such 

 studies, however, have been far from satis- 

 factory. It is known that sunspots have a 

 different period of rotation, according as 

 they are near or far from the equator, and 

 this fact is enough to show the extremely 

 dubious nature of an attempt to fix on any 

 definite period for recurring solar eflects. 

 It is not at all surprising that more than a 



