More Enquiries into Mason-bees 



To treat an Insect as you would a mag- 

 netic needle and to subject it to the current 

 from an induction-coil in order to disturb Its 

 magnetism or diamagnetism appeared to me, 

 I must confess, a curious notion, worthy of 

 an imagination in the last ditch. I have but 

 little confidence In our physics, when they pre- 

 tend to explain life; nevertheless, my respect 

 for the great man would have made me re- 

 sort to the Induction-coils, If I had possessed 

 the necessai-y apparatus. But my village 

 boasts no scientific resources: If I want an 

 electric spark, I am reduced to rubbing a sheet 

 of paper on my knees. My physics cupboard 

 contains a magnet; and that Is about all. 

 When this penury was realized, another 

 method was suggested, simpler than the first 

 and more certain In Its results, as Darwin him- 

 self considered: 



"To mak" a very thin needle Into a mag- 

 net; then breaking It into very short pieces, 

 which would still be magnetic, and fastening 

 one of these pieces with some cement on the 

 thorax of the Insects to be experimented on. 

 I believe that such a little magnet, from its 

 close proximity to the nervous system of the 

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