584: 
ArTICLE XXIX. 
On the Application of Circular Polarization to Organic 
Chemistry ; by M. M. Bior and CHEVREUL. 
On the Application of Circular Polarization to the Analysis 
of the Vegetation of the Graminee; by M. Bror. 
(Read before the Royal Academy of Sciences of Paris, July 1st, 1833.) 
From the Nouvelles Annales du Muséum d@ Histoire Naturelle, vol. iii., p. 47, sq. 
Ir being my intention to show by experiment in what manner indica- 
tions derived from circular polarization may be usefully employed in 
chemical researches, principally in those of organic chemistry, the 
innumerable transformations effected in carbonated products by vege- 
table life appeared to me to be one of the objects of study best adapted 
for the attainment of this end. For these products, so various in their 
appearances and physical properties, being, under an infinity of circum- 
stances, composed solely of carbon and water united in different pro- 
portions, their mixtures, combinations, and transmutations, offer ex- 
cellent tests of a method which distinguishes them individually by 
inspection alone, and thus ascertains their presence without altering 
them. Now organic chemistry was deficient in precisely these cha- 
racters recognisable by inspection, the consequence of which was its 
difficult, I may even say its often uncertain progress; because, being 
unable to recognise bodies otherwise than by isolating them, and this 
isolation being effected only by the intervention of special agents 
applied to the combinations or mixtures of which they form a part, the 
choice and appropriation of the tests to be employed for each case 
could only be determined by the conjecture, more or less probable, of 
their presence ; and there is often danger of modifying these products 
by thus acting upon them, or even of creating new ones by uniting the 
principles of which they are formed ; so mobile are the combinations 
upon which they depend, and with such facility do they become con- 
verted into each other. - 
The indications (caractéres indicatifs) furnished by circular polari- 
zation certainly will not remove these last-mentioned difficulties, which 
are inherent in the subject ; but in very many cases they will abridge 
and reduce them to those which are inevitable, by in the first instance 
furnishing the chemist with the properties capable of being immediately 
observed, predicable of the molecular condition of the combinations on 
which he has to treat; then by rendering equally visibleand observable 
all the changes by which that primitive state may be altered, so that 
