that it is rather the study of chemical action than the particular study of this or that substance as such that tends to improve the method of work. In this way many obscure substances have contributed largely to the improvement of chemistry, and consequently to the improvement of pharmacy. There is a not uncommon feeling that it is a waste of time to work for years endeavoring to unravel the secrets of some apparently insignificant substance. If the substance itself can not be used, and there is no prospect that it ever can be used, then, it is argued, it can not be important. To you, gentlemen, who have been under especially good instruction in these matters, this argument will not appear to be of much weight, but permit me to turn my attention for a moment to the larger audience before us, and to say a word in defense of those who spend their lives in what are commonly looked upon as unprofitable investigations.
Not long ago I heard this story, which may serve as a sort of overture to what I want to say: An excellent gentleman, on being informed that a certain scientific man was engaged in work upon frogs, replied, "Why spend his time in such trivial work, when there is the human soul to investigate?" The feeling which actuated the speaker is one which I repeat is not uncommon, and I may add it is quite natural, but it is certainly wrong in principle. If we analyze the underlying thought of those who cavil at ordinary scientific investigation, we shall find that there are two distinct ideas contained in it: First, that, in order that any investigation shall be of value or of importance, it must bear direct fruit. The substance discovered must be useful for some "practical" purpose, either as a medicine or as a dyestuff, an explosive or a poison—no matter what, so that it can be used for something. A second idea is that, in order to solve the problems of nature, only those of the most evident importance should be attacked. Such questions as What is life? What is electricity? What is the attraction of gravitation? What is force? What is matter?—these are the ones which, in the opinion of many, should occupy investigators, to the exclusion of the less important.
As regards the latter idea, it may be said that there are a great many very strongly fortified citadels in nature. Scientific investigators have attacked these from time to time and have been repulsed. A good commander, having discovered that a stronghold is invulnerable from a given point, does not continue to attempt its capture from that side, but looks around him for other means of approach; he strengthens his forces, he collects more ammunition, and endeavors to keep his army in general in good condition, studying the surrounding country, and awaiting new revelations. There is, further, a great deal of insignificant camp-work to be done, and, if this is neglected, ultimate success can not be hoped for.
So, too, the scientific investigator finding that a certain problem of paramount importance can not be solved, turns his attention to