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SELECTED ARTICLES. 
more important part in nature than we as yet have been 
tempted to suppose. I, therefore, will name it, following an 
etymology well known in chemistry, the catalytic force 
of bodies; and the decompositions which it determines, cata- 
lysis, in the same way as we designate by analysis the 
separation of the elements of a compound by means of the 
ordinary affinities of chemistry. This force appears to consist 
definitely in a faculty of bodies to set in action, by their simple 
presence, the play of certain affinities, which at that tempe- 
rature remain inactive, so as to determine, in consequence of 
a new re-division of the elements of the compounds, a new 
state of perfect chemical neutralization. As this force acts, 
in general, in a manner analogous to heat, we may ask whe- 
ther, when differently graduated, either by a different use 
of the catalytic body, or by the introduction of different 
catalytic bodies in the same liquid, it would give rise, as has 
been observed in the action of heat and different temperatures, 
to different catalytic products? The existence of this definite 
force, spreads a light altogether new upon the chemical re- 
actions of organic bodies. We will cite but one example. 
Around the eye of the potato diatase is found accumulated, 
which, on the contrary, is entirely wanting in the developed 
germ; and in the tubercle we recognise in this point a centre 
of catalytic action, from which the insoluble amidon of the 
tubercle is changed into gum and into sugar, and this part of the 
potato becomes the secretary organ for the soluble substances, 
which form the juices — the nourishment of the growing germ. 
It is hardly probable that the action mentioned should be the 
only one of the kind in vegetable life; we may on the con- 
trary presume, that, in vegetable, as well as in the animal bodies, 
a thousand catalytic effects take place between the tissues and 
the liquids; from whence exactly result the great number of 
different chemical compounds, the production of which at the 
expense of the same crude matter, which we call blood and 
vegetable juice, cannot be explained by any other known cause. 
Journ. de Chim. Med. 
