53 SCIENTIFIC ILLUSTRATIONS [Con 



Compensation in Modes of Power. 



If an insect's power of flying is not considerable, its power 

 of traction and propulsion are immense compared with the 

 vertebrate animals, and in the same group of insects those that 

 are the smallest and lightest are the strongest. The proportion 

 between the muscular strength of insects, and the dimension of 

 their bodies, would not appear to be on account of their muscles 

 being more numerous than those of the vertebrate animals, but 

 on account of greater intrinsic energy and muscular activity. 



I. 



The Limits of Compressibility. 



Compressibility is the property in virtue of which the volume 

 of a body may be diminished by pressure. This property is 

 at once a consequence and a proof of porosity. Bodies differ 

 greatly with respect to compressibility. The most compressible 

 bodies are gases : by sufficient pressure they may be made to 

 occupy ten, twenty, or even a hundred times less space than 

 they do under ordinary circumstances. In most cases, however, 

 there is a limit beyond which, when the pressure is increased, 

 they become liquids. The compressibility of solids is much less 

 than that of gases, and is found in all degrees. Stuffs, paper, 

 cork, woods, are amongst the most compressible. Metals are 

 so also to a great extent, as proved by the process of coining, 

 where the metal receives the impression of the die. Here also 

 there is in most cases a limit beyond which, when the pressure 

 is increased, bodies are fractured or reduced to powder. So, 

 too, with bombastic sermons, and with sensational newspaper 

 articles. Compression reduces the former into sentimental 

 drivel, and the latter into intellectual dust. EL. 



Conduct Shaped by Constitution. 



Among the Albinos of the Isthmus of Darien, the practice of 

 sitting up at night and sleeping in the day is prevalent. Speak- 

 ing of them, "Wafer, an old traveller, says : " They see not well 

 in the sun, their eyes being weak and running with water if 



