THE INTEGUMENT, OR SKIN 69 



seemed of unusual shape and dimensions. He had just returned 

 from taking the benefit of the sun, and after a cold bath, and a slight 

 repast, had retired to his study." Then follows a description 

 of the destruction of Pompeii, and the death of the elder Pliny. 



31. We may judge somewhat of the benefits of the sun, by 

 observing the unnatural and undeveloped condition of plants 

 and animals which are deprived of light. Plants become 

 blanched and tender ; the fish of subterranean lakes, where the 

 light of day never enters, are undersized, and have no eyes ; 

 tadpoles kept in the dark dp not develop into frogs; men 

 growing up in mines are sallojv, pale, and deformed. Besides 

 the well-known effect of solar light in tanning the skin, it also 

 makes it thicker and better able to resist exposure; though 

 the complexion may be thereby injured, the health gained 

 more than compensates for the loss of beauty. "To make 

 good the loss of the lily, where the sun has cast his ray, he 

 seldom fails to plant the rose." (Read Notes 9 and 10.) 



32. Clothing.* In reference to clothing, we are far more 

 apt, in our changeful climate, to use too little than too much. 



9. Light Influences Growth and Health. "I have several times 

 taken two potatoes which were as nearly as possible alike, and placed 

 one under a bell-glass through which the light could pass, and the other 

 under a similar cover rendered opaque by several coats of black paint. 

 Sprouting went on unchecked under the translucent glass, while it was 

 always notably retarded and sometimes prevented in the potato under the 

 dark glass. Milne Edwards, a distinguished French physiologist, per- 

 formed a series of experiments which showed that tadpoles when deprived 

 of light did not develop into the frog. I have several times repeated his 

 experiments, and always with confirmatory results. On one occasion I 

 prevented for one hundred and twenty-five days the development of a 

 tadpole, by confining it in a vessel to which the rays of light had no 

 access. On placing it in a receptacle open to the light, the process of 

 transformation was at once begun, and was completed in fifteen days. 

 The practical application of these and similar observations is this, that 

 core should be taken both in health and disease to insure a sufficient 

 amount of sunlight to the inmates of Houses, and that it is impossible to 

 rear well-formed, strong, and robust children unless attention is paid to 

 this requirement." Hammond on the Influence of Light. 



* Man is the only animal that requires clothing ; and as he advances 



81. Benefit of the sun ? Effect upon plants ? Skin ? 



82. Direction about clothing f Exposing limbs of children ? Clothing, night and day f 



