Small-pox and measles) unknown or imperfectly known to the Greeks; the only real advance was in pharmacy and the therapeutical use of drugs.
It is enough to say that on this fantastic basis Helmont constructed a medical system which had some practical merits, that his therapeutical methods were mild and in many respects happy, and that he did service by applying newer chemical methods to the preparation of drugs.
In practical medicine the subsequent results of Behring and his followers have in diphtheria attained a signal therapeutical success.
If we consult the medical works even of the middle of the 19th century we shall find that, in the light of the present time, accurate knowledge in this sphere, whether clinical, pathological or therapeutical, could scarcely be said to exist.
In France, in the wards of the Hotel Dieu, Guillaume Benjamin Duchenne (1806-1875), in association with Trousseau and in his private clinic, pursued his memorable clinical and therapeutical researches into the diseases of the nervous system; and Jean M.