others, the solution of which may in the end contribute to clearing up greater mysteries. There are hosts of minor questions to be answered, and these must be answered before the fundamental questions of nature can be. Through the insignificant lie the roads of advancement. A fallen leaf, a bit of stone, a tiny flower, a microscopic animal, may contain within themselves the answers to the most important questions. It is not the leaf, or the stone, or the animal that is specially investigated, but the principles involved in their existence. Explain these, if possible, and the explanations will serve for a thousand other things. Then, too, though the explanations sought for may not be found, the correct study of any fact or phenomenon of nature is of assistance to science as a whole. It strengthens her forces, it supplies her with ammunition. An enormous amount of camp-work must be done, or results of value can not be attained. Let the work upon the insignificant problems cease, and the world would sink into darkness. To fully understand the laws of the universe as a whole, we must first learn all we can in regard to the smallest subdivisions of the universe—the atoms.
As regards the idea that an investigation must bear direct fruit to be valuable, I would say that the reply to this is contained partly in what I have already said, but it can be refuted much more clearly and appropriately for our present purpose by the consideration of an example or two. As I remarked a few minutes since, when a new substance is discovered by a chemist, the first question asked by most persons is, What is it good for? what can it be used for? As I desire to show that pharmacy is much indebted to chemistry in recent times, it would seem that I ought first to show that many new substances have been discovered by chemists which are of use in pharmacy. This is, however, so obvious that I prefer to show how some of the most abstruse chemical investigations may ultimately yield fruit of much value to pharmacy. In an address which I had the honor to deliver a few years ago in this building, before the "Medical and Chirurgical Faculty of Maryland," I referred to the purely scientific investigations which led to the discovery of choral, and to a method for the manufacture of salicylic acid on the large scale. It can easily be shown that these discoveries were made, not because the discoverers were attempting to find substances gifted with the properties which these two are known to possess, but that they were made as the result of abstruse chemical investigation, undertaken simply with the object of adding to the possessions of science. I shall not repeat what I then said, for there are enough new examples, as well as old, to furnish us with interesting material.
Of comparatively recent discoveries, which may be classed among those which are of direct importance to pharmacy, is that of the artificial preparation of the oil of mustard. This substance is now made by a patented process entirely independently of the mustard-plant. I