128 tOPDLAE EEEOBS. 



prudent housekeeper preferred to take no chances, 

 choosing to sacrifice her desire for the beautiful 

 rather than to risk in any degree the health of her 

 family. And so the house plants during the 

 winter season, when they could not be exposed to 

 the open air at night, to exhale without harm their 

 poisonous gases, were consigned to the cellar until 

 the following spring, thus depriving the household 

 of their presence during the period when they were 

 most needed. 



This result led the florists, who were financially 

 interested in the question, to further investigation. 

 It was then found that the alternation in the exhal- 

 ations of plants between the day and night was 

 more apparent than real. They brought out the 

 fact that it had been proved that plants would 

 absorb in a few minutes of sunlight more carbonic 

 acid than would be given out during the whole 

 night. They also showed that all the plants that 

 could be kept in a living room would not give off 

 as much carbonic acid gas as would be given off by 

 one person. They further pointed out the fact 

 that persons might sleep night after night in a 

 green house filled with growing plants without 

 injury to their health. This fact, accompanied by 

 the repeated explanation of what actually takes 

 place in plant respiration, soon disabused the popu- 

 lar mind of the idea that plants are necessarily 



