THE INFLUENCE OF PLANTS IN ROOMS. 
223 
surrounding atmosphere unalloyed oxygen, takes 
place under the influence of sunlightand it will 
be granted that its hygienic effect will be most 
potent in the open air or in the sunnier part of a 
house. Still, the process is not entirely arrested 
by the absence of sunlight, and its operation—so 
far as its beneficial influence is concerned—must 
be taken in conjunction with the absorption of 
carbonic acid gas and the resulting respi¬ 
ration of oxygen by the hardier Ferns and the 
sun-loving plants in the sunnier windows of a 
house. 
It must, however, be conceded that if the sug¬ 
gestions in this volume be adopted to the extent 
the Author would desire, and Ferns are intro¬ 
duced into every possible corner of a house, so 
great an importation of plant life—involving pre¬ 
sumably a large addition to the previous stock of 
plants of those householders who, for the first 
time, carry out the proposals of the Author— 
cannot but exert a very important hygienic in¬ 
fluence upon the normal condition of the atmos¬ 
phere of a dwelling-house. Will it not, indeed, be 
admitted, then, that there is an especial reason— 
