STORAGE, RESPIRATION, AND GROWTH. jul 
that the acid flavor of green fruits was produced by oxygen, which 
was only very teebly held in combination in the fruit. 
This first paper by Couverchel gives results of the analysis of juice 
of apricots and grapes at different stages of growth, determinations of 
density, acidity, dry weight (in vacuo), gum, sugars (weighed as dried 
sirup), ash, and soluble ash. 
In the second contribution, in 1831,¢ further quotations from early 
writings are given. Of much interest is that from the work of 
Ingenhouz:? 
All fruits, day and night, exhale a mephitic air, and possess the power to render 
the surrounding air unwholesome. I have been very much astonished to find a 
poison in fruits which are so much eaten, the more since the finest fruits possess 
this power in high degree. * * * 
Couverchel differed from his predecessors, believing the presence 
of air to be only incidental in the ripening of fruits, and that ripening 
@oes on by action of principles contained in the fruit. It may be, he 
says, that the sap becomes acidified in its passage through the young 
branches to the ovary by reason of the decomposition of water and 
absorption of the oxygen. The acids so formed may act on the gela- 
tin and give rise to sugars, sugars being considered as intermediate 
substances between the mucilages and the vegetable acids, containing 
more oxygen than the former and less than the latter. 
In 1844 Frémy¢ discussed the work of Bérard on the respiration of 
fruits. He confirmed the observation that fruits consume oxygen, 
giving off carbon dioxid, and carried out an experiment similar to 
those of Bérard. In Frémy’s work the unripe fruit, attached to the 
tree instead of being kept in a closed jar as in the experiments of 
Bérard, was coated with varnish, in this way stopping the normal 
respiratory changes. (Growth was found to cease, as in the experi- 
ments of Bérard. 
The air contained in green and in ripe fruits was analyzed by boiling 
slices of the fruit in brine and analyzing the air which separated. 
The presence of a ferment causing the respiratory changes was sug- 
gested, although a pear, after it was ground, gave off no carbon dioxid 
gas, whereas before grinding carbon dioxid was freely evolved. 
The old idea that the acids change in ripening (see p. 10) was refuted 
in the case of grapes, by the recognition of tartaric acid in the very 
young fruit. 
Unripe fruit was profoundly altered by soaking in dilute sodium 
carbonate, but no conclusions are drawn. Objection is made to the 
statement that starch can form the sugar found in fruit, since the sugar 
«Loe. cit. 
bVersuche mit Pflanzen, 1786, 1: 64; 2: 61, 221, through Gerber, loc. cit. 
¢Compt. rend., 1844, 19: 784. 
