FOR DISTINGUISHING SACCHARINE JUICES. 597 
of others or leads to their prediction, since it has a tendency to confound 
two very different bodies, and since on the other hand it establishes a 
difference between two bodies which in other respects have the greatest 
analogy of properties and composition. 
It does not therefore fulfill the conditions 18 6 ed. 
21. From the manner in which M. Biot has related his observations, 
it appears to me that, in the actual state of things, the property of caus- 
ing a deviation in the plane of polarized light is in its variations con- 
nected rather with the various arrangements that the particles of a species 
may take without their nature being altered, than it is with the various ar- 
rangements which constitute different species ; so that there is not now 
more reason to establish a mutual relation between species which act in 
the same direction and with the same energy, than there is to presume 
that a decided opposition exists between the properties of two species 
which act differently upon the plane of polarization. 
§ 2. 
On the probable Utility of the Optical Character. 
22. I have stated the objections which may be urged against the use 
of the optical character as it has been presented by its author ; I shall 
now consider in what it is likely to be useful. By this mode of examining 
the physical character, the application of which to organic chemistry 
has been proposed, I hope to render apparent the object which I 
have really in view, which is to restrain within its true limits that which 
has been made to exceed them by ascribing to it a generality which 
_ it does not possess, and a degree of precision which it can only attain 
by ulterior experiments, and which even then will be confined to the 
_ limits which J attribute to it. 
_ ArticLe I.— Utility of the Optical Character for the various Ar- 
rangements of the Atoms or Particles of a Species. 
_ 93. If it be true, as M. Biot thinks, that a body, as grape sugar, 
though dissolved in water, affects the molecular state in such a man- 
"ner as to cause deviation to the right or left of the plane of polarization, 
accordingly as the solution has been made with crystallized sugar, or is 
such as nature presents us with in the juice which has just been ex- 
tracted from the grape, it is undoubtedly interesting to inquire whether 
other species of immediate principles present an analogous phenome- 
non, in order to judge whether any consequence may be deduced, re- 
lative either to the various arrangements of which the atoms or parti- 
eles of these species taken separately may be susceptible, or to the 
cause which produces the variation of the phenomenon. 
_ 24, When the object of study is a species of body brought to its 
282 
