published in Paris. Chemistry, at this period[109] took possession of the schools, and whilst it was gradually grafted into the theory of medicine, it soon became the only guide to its practice, the absurdity of which has been already dwelt upon. In tracing the march of chemical improvement during the last century, we cannot but be struck with the new and powerful remedies which it has introduced, and the many unimportant and feeble articles which it has dismissed from medical practice. In the present century, the rapid progress of Chemistry has outstripped the anticipations of its most sanguine votaries; and even in the department of vegetable analysis, a correctness has been attained, the very attempt at which had been abandoned by the most illustrious chemists of the former age as hopeless and chimerical; let us for instance only compare the results obtained by the Academicians of Paris, and published by Geoffroy, in their analyses of several hundred plants by the operation of heat, with the elegant and satisfactory researches in this branch of science lately conducted in the same country; whilst the former failed in establishing any distinction between the most inert and the most poisonous plants, the latter have succeeded in detecting, separating, and concentrating several of their most subtile constituents. _Opium_ has been at length compelled to confess its secret source of action, and _Ipecacuan_ to yield its emetic element in a state of perfect purity. Our Pharmacopœias and Dispensatories[110] have cautiously kept pace with the scientific progress of the age; and in tracing them from their origin to the present time[111] it is gratifying to observe the gradual influence of knowledge in reducing the number of their articles—simplifying the composition of their formulæ—and improving the processes for their preparation.[112] Chemistry has also been the means of establishing the identity of many bodies which were long considered as specifically different; thus an extensive list of animal substances has been discarded, since it is known that they owe their properties to one and the same common principle, as to _gelatine_, _albumen_, _carbonate of lime_, &c.; so again the fixed alkaline salt produced by the incineration of different vegetables, has been found to be potass, from whatever plant it may have been obtained, with the exception of sea plants, and perhaps some of the Tetradynamia, the former of which yield _Soda_ and the latter _Ammonia_. Previous to the Pharmacopœia of 1745, every vegetable was supposed to yield a salt essentially different, and therefore a number of alkaline preparations were recommended, each bearing the name of the particular plant from which it had been procured, as salt of _Wormwood_—salt of _Broom_,—_Salt of Bean-Stalks_, &c.