ON THE RIPENING OF FRUITS ETC. 151 
ART. XXXII.— ON THE RIPENING OF FRUITS AND THE 
GELATINOUS PRINCIPLES OF VEGETABLES. 
By E. Fkemy. 
The author gives the following summary of the facts de- 
tailed in his memoir on the above-named subjects I'- 
ll There exists in the tissues of vegetables, and princi- 
pally in the pulps of fruits and of roots, a substance insolu- 
ble in water, which he has named pectose ; its characteristic 
property is that of being converted into pectine, by the in- 
fluence of the weakest acids. It diners essentially from 
cellulose in all its properties. 
2. Pectine exists in the juices of ripe fruits ; it may be 
artificially obtained by causing boiling weak acid liquors 
to act upon pectose. Pectine ought to be considered as a 
weak acid ; it does not precipitate the neutral acetate of 
lead, and changes into pectic acid under the influence of 
soluble bases. 
3. Pectine, submitted for some time to the action of boil- 
ing water, acquires the property of precipitating neutral 
acetate of lead, and is converted into a new substance 
which M. Fremy calls parapectine ; it is neutral to test- 
papers, and occurs in the juices of perfectly ripe fruits. 
4. Parapectine is transformed, under the influence of 
acids, into a substance which the author calls melapectine; 
it has the properties of a weak acid, reddens tincture of 
litmus, and precipitates chloride of barium ; it may be 
named metapeciinic acid. 
5. The preceding substances form compounds which are 
soluble in a certain number of acids, and principally with 
sulphuric and oxalic acids. These compounds are crystal- 
lizable, and form gelatinous precipitates with alcohol. 
6. There accompanies pectose in vegetable tissues, a 
peculiar ferment called by M. Fremy pectase ; this has the 
property of transforming pectine successively into two gela- 
