THE INFLUENCE OF PLANTS IN EOOMS. 
surrounding atmosphere unalloyed oxygen, takes 
place under the influence of sunlight ; and 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 — 
207 
