338 The Exhalation of Ozone by Flowering Plants, [Api 
In my readings, while preparing earlier memoirs on some plast 
functions, I would not infrequently meet with statements to tie 
effect that some sort of relationship exists between vegetation i 
and particularly forest growth, and the ozonic condition of te 
atmosphere. Thus, as stated in a former paper, a Dr. Schreibe 
maintains that the emanations from pine forests actively conet 
the oxygen of the air into ozone, but upon what basis of truth! 
any, the statement rests, [ have not learned. A. Naquet sji . 
“ Ozone exists in woods and fields and wherever there is actine 
vegetation.” Itis evident that assertions of a general character 
like the above, without experimental proof, are of no real saet 
tific value. On the other hand, the solution of so importanta 
question as whether plants generate or convert the oxygen of 
air into ozone, could not fail to be hailed as a noteworthy adas 
in scientific knowledge. 2 
For more than a year past the writer, while engaged p 
active practice of his profession, has devoted his intervals ® | 
leisure to an experimental investigation of the subject. ay 
nary to giving in detail the results of these experiments, n 
thought proper to speak of the various tests for the dn 
ozone, and to point out the relative merits of the same. an 
dicative of the difficulties of making such tests, pare F 
scopes have from time to time been devised, most of which ! : 
proved highly unsatisfactory. <i 
. lo: has 
Dr. A. R. Leeds, of Stevens Institute of Techno o 
an investigation into the relative merits of some half ike 
ing tests for ozone (Chem. News for May, 187 8). Wi i ai 
a detailed account of his observations, it will suffice or k 
to state a few of his conclusions. The Schoenbein or 
starch test was found to be most sensitive. It a rai 
that this test was used in all my observations. — Dr. f. 
test, which was also employed in our exper! go 
oderately Sê 
and whet ® 
” 
tened occupying a position midway 
sensitive, and those least so to the influence | 
In the National Board of Health Bulletin 
Dr. J. H. Long, under the auspices of the A made it 
sociation, records the results of ozone observati f 
ent places throughout the United States, bya 
of ozone. 
