Page:The Harveian oration delivered at the Royal College of Physicians June 26, 1889 (IA b22361285).pdf/43

 method that we owe the discovery of most of our highly prized drugs, especially the remedies known as ‘specifics,’ nearly all of which have been made known to us by mere accident. Thus quina, iodide of potassium, bromide of potassium, and colchicum, which in certain diseases we prescribe with great confidence, came before us having no claim upon our attention beyond the fact that certain persons had tried them as remedies without being able to give any good reason for having done so. It is very interesting to watch the efforts making, as science advances, to cast light on this great question of therapeutics.

We find chemical philosophers interesting themselves in attempting to trace a relation between the physiological action of a substance and its chemical composition and constitution. Chemical composition scarcely helps us, however; for though it has been shown that salts of the same base occasionally resemble each other in their action upon the economy, still the opposite is so often the case that we cannot hope for much assistance here. A fact mentioned by Bunsen is again remarkable in its relation to this subject. That observer has shown that kakodylic acid, which contains more