M. C. Lea on the Infiuence of Ozone, etc. 373 
Art. XXXIV.—On the Influence of Ozone and some other Che 
Chem- 
ical Agents on Germination and Vegetation; by M. Cargy LEA, 
Philadelphia. 
and the labors of Boussingault, Knop, Stohmann, Ville, Sachs, 
and many others, are daily adding to our stock of knowledge 
and developing new and interesting fac he studies of these 
chemists have, however, been directed almost entirely to the effects 
of the absence or presence in greater or less proportion in the soil 
of those bases and acids which are there commonly found. With 
respect to other agencies, little has been done since the valuable 
investigations of ‘l'urner and Christison, made more than thirty 
years ago, in which they examined the effects of chlorhydric 
and nitrons acid gases, chlorine, sulphuretted hydrogen, cyano- 
gen and some other gases. Géppert about the same time pub- 
lished some investigations upon the influence of cyanhydric acid. 
The effect of all these substances was very much what mi 
have been anticipated from their tendency to attack organic 
ssues, : 
The examinations which I propose here to describe have been 
made in a somewhat different direction. The most curious result 
obtained appears to me to be that relating to the effect of a highly 
ozonized atmosphere upon the roots of plants. I have also found 
nde 
tirely neutral, may exercise a powerfully poisonous influence 
upon vegetation, when disseminated in the atmosphere sur- 
ounding it. 
Pated before introducing it beneath the bell glass. 
Two sets of experiments were made: in the first, the water 
with which the seeds came in contact was made to contain those 
Solid substances which are most essential to vegetation. In the 
