XXIII. 



ARE HOUSE PLANTS INJUEI0U8 TO 

 HEALTH? 



THE custom of having plants in our houses has 

 now become so common in this country that 

 there appears hardly anywhere to exint a doubt in 

 regard to the propriety of the practice. It is but a 

 few years, however, since it was earnestly discussed 

 whether the presence of plants in living rooms, and 

 especially in sleeping rooms at night, was not in- 

 jurious to health. The idea that plants so kept 

 were prejudicial to the health of persons occupying 

 the same rooms at night arose from the reported 

 discovery that while plants absorbed the injurious 

 carbonic acid gas from the air during the day, and 

 gave ofP at the same time the life-giving oxygen, 

 that at night the process was reversed, oxygen 

 being absorbed and the deadly carbonic acid given 

 off. The alternation of the process appeared 

 natural enough; it was easy to remember, and it 

 was accepted without further thought as scientific 

 truth by many persons who possessed but a super- 

 ficial knowledge of the actual condition of things. 

 The danger at least seemed probable, and the 



(12T) 



