302 BIOGRAPHICAL SKETCHES. 
the subtle perspicacity which he brought to bear at a glance upon 
plants, often wholly new to him, taught me much of the art of ob- 
serving, and especially of combining observations in botany. To 
such talents he joined a lofty soul and a heart devoted to friendship. 
it was a great grief to me when, at over sixty years of age, he quitted 
Europe to rejoin in Brazil the king who had persecuted him ; but 
he forgot all his wrongs when his sovereign became unfortunate. 
Correa died when ambassador to the United States.” 
The following, of a somewhat later period, is abridged from 
De Candolle’s account of the Société d’Arcueil : — 
* Its founder was the excellent and illustrious Berthollet, who, then 
living in his country residence at Arcueil, . . . invited thither, once 
a month, a few young savans, by way of encouraging their efforts. 
His colleagues MM. de la Place and Chaptal, also senators and 
members of the Institute, were, so to say, vice-presidents of this 
little reunion. Humboldt also had a place, and the parterre was 
composed of Biot, Thénard, Gay-Lussac, Descotils, Malus, Amédée 
Berthollet, and myself. Later, Berard and Francois de la Roche 
were admitted. [And finally Arago, Poisson, and Dulong, adds the 
editor, who notes that the last volume of the “* Mémoires d’Arcueil ” 
was published in 1817.] The association was devoted to the physical 
and chemical sciences. I was admitted in view of the applications 
of vegetable physiology to chemistry; and I contributed some arti- 
cles upon this subject to the ‘Mémoires d’Arcueil,’ namely, my 
Note on the cause of the direction of stems towards the light, my 
Memoir on the influence of absolute height upon vegetation, and 
upon the geographical or topographical distribution of plants, and, 
later, one upon double flowers, especially of the Ranunculacee. 
The first of these writings was a simple and clear solution [although 
an incorrect one, as it proves. — Eps.] of a problem which was 
deemed insoluble; the second reduced to just proportions the ex- 
aggerations of Humboldt upon the influence of elevation ; the third 
was an essay connected with the observations of the degenerescence 
of organs, to which my ‘ Théorie Elémentaire ’ was devoted. . . . 
**We commonly made our rendezvous at Thénard’s, and went 
together to Arcueil, as happy with this run into the country as 
schoolboys out for a holiday. We walked about in this pleasant 
villa, and relished the society of our leaders. Nothing can fully 
describe the good-nature and simplicity of M. Berthollet and even 
of Madame. They were with us as parents with their children, and 
