i 9 4 THE POPULAR SCIENCE MONTHLY. 



what quick and feeble ; their countenance is pale ; the lips are not un- 

 frequently somewhat "blue ; and the tongue is covered with a thin, 

 whitish, and somewhat slimy fur. The appetite is in abeyance ; there 

 is a feeling of nausea ; and the first evacuation is generally dark in 

 color. 



What is the pathological condition of such patients at this mo- 

 ment? Simply this: The blood contains an excess of carbonic acid, 

 which, circulating with the blood through every organ, disturbs the 

 natural action of every organ, blunting its sensibility, vitiating its par- 

 ticular function, and interfering with those molecular changes which 

 constitute healthy nutrition. 



A person thus affected does not usually die. The body, removed 

 to a pure atmosphere, begins at once to excrete the carbonic acid by 

 the lungs, the liver, the skin, the kidneys, and the bowels, and in the 

 course of a few. hours the more visible manifestations of its baneful 

 effects have passed away. It, however, often happens that a sense of 

 weariness and muscular debility is felt for days afterward. Night, 

 too, frequently places such subjects in the same condition as before. 

 The same bedroom is occupied ; the same inadequate means of ventila- 

 tion continue ; the same accumulation of carbonic acid takes place ; 

 and the same effects upon the bodily organs are repeated. Blood 

 charged with an excess of carbonic acid again pervades every tissue of 

 the heart, diminishing its vitality, lowering its sensibility, and assimi- 

 lating its nutrition to that of the reptilian heart. But the low char- 

 acter of the nutrition of the reptilian heart does not accord with the 

 comparatively quick circulation, rapid nutrition, vital power, and 

 energy of action required by the human heart. The one cannot be sub- 

 stituted for the other. In man the change results in disease where 

 disease does not exist aggravates disease where it is already present. 

 Lancet. 



* 



FORESTS AND FRUIT-GROWING. 



By J. STAEL PATTERSON, Esq. 



FRUIT has become a necessary of life a great variety of fruit 

 indeed, and a great deal of it ; and this will become more and 

 more the case with the increase of intelligence and thrift. The great 

 abundance of most kinds of fruit for the last two or three years may 

 cause us to feel a security, which is not well grounded, with regard to 

 the conditions of climate necessary to the unfailing production of fruit. 

 Only within a few years past have there been seasons w T hen the fruit- 

 crop was very light, and not at all adequate to the demand. One of 

 the causes of this is the capriciousness of the seasons, and this capri 



