496 
SECOND REPORT — 1 832 . 
Part III .—Organic Chemistry. 
Section I. Vegetable products .—The attention of chemists, 
long withheld from the department of vegetable chemistry by 
the obscurity and difficulty of the subject, has of late years been 
more earnestly directed to this interesting field. The analyti¬ 
cal researches of Gay-Lussac and Thenard threw the first di¬ 
stinct light on the nature of vegetable compounds, and gave 
rise to the first general deductions in regard to their composi¬ 
tion. Those of Saussure and of other chemists, whom the ap¬ 
parently simple method of analysis employed by Gay-Lussac 
induced to undertake similar investigations, speedily added to 
the number of ultimate analyses. But the dissimilar and often 
contradictory results obtained by different experimenters in ana¬ 
lysing the same substance, showed that few of those yet made 
known could be regarded as anything more than tolerable ap¬ 
proximations. The determinations of Berzelius and Dr. Prout 
were among the earliest on which confidence could be placed, 
and have proved almost the only ones which later investigations 
have not corrected. 
In different countries attempts have been made to improve 
the method of vegetable analysis, so as to secure more constant 
and more exact results. In England, Dr. Prout’s apparatus, 
though less simple than that employed by others, has in his 
hands led to results of the greatest precision. In France, Du¬ 
mas, Pelletier, Henry and Plisson, and others, have paid much 
attention to this subject. In Germany we owe to Liebig and 
Wohler many of the best and most important analyses hitherto 
published on vegetable chemistry. 
Another description of labourers also has done much in this 
field. The remarkable discovery of Serturner, that the opium 
of commerce contains a vegetable alkali or salt basis (morphia), 
to which its soporific virtues are owing, led the way to a train 
of vegetable research, from which large accessions of know¬ 
ledge have been obtained. Pelletier and Caventon had the 
merit of first following up the investigation, and of making us 
acquainted with several of the most important vegetable prin¬ 
ciples hitherto discovered. They have been followed by many 
others, and with such success that during the fifteen years 
which have elapsed since Serturner’s discovery began to attract 
the attention of chemists, we have been made acquainted more 
or less fully with upwards of thirty acid and nearly as many 
alkaline principles, either existing ready formed in the products 
of the vegetable kingdom, or produced during the process em¬ 
ployed for extracting their active ingredients. Besides these, 
