I4<> SCIENCE SKETCHES. 



" A .man cannot be professor of zoology on one 

 day and of chemistry on the next, and do good 

 work in both. As in a concert all are musicians, 

 one plays one .instrument, and one another, but 

 none all in perfection." 



" You cannot do without one specialty. You 

 must have some base-line to measure the work and 

 attainments of others. For a general view of the 

 subject, study the history of the sciences. Broad 

 knowledge of all Nature has been the possession 

 of no naturalist except Humboldt, and general 

 relations constituted his specialty." 



" Select such subjects that your pupils cannot 

 walk out without seeing them. Train your pupils 

 to be observers, and have them provided with the 

 specimens about which you speak. If you can 

 find nothing better, take a house-fly or a cricket, 

 and let each one hold a specimen and examine it 

 as you talk." 



" In 1847 I gave an address at Newton, Mass., 

 before a Teachers' Institute conducted by Horace 

 Mann. My subject was grasshoppers. I passed 

 around a large jar of these insects, and made every 

 teacher take one and hold it while I was speaking. 

 If any one dropped the insect, I stopped till he 

 picked it up. This was at that time a great inno- 

 vation, and excited much laughter and derision. 

 There can be no true progress in the teaching 

 of natural science until such methods become 

 general." 



11 There is no part of the country where in the 

 summer you cannot get a sufficient supply of the 

 best specimens. Teach your children to bring 



