During the fourteenth century, Arnold of Villanova, the inventor of nitric acid, and the two Hollanduses, kept up the tradition of original investigation in chemistry. Altogether there are some dozen treatises from these three men on chemical subjects. The Hollanduses particularly did their work in a spirit of thoroughly frank, original investigation. They were more interested in minerals than in any other class of substances, but did not waste much time on the question of transmutation of metals. Professor Thompson, the professor of chemistry at Edinburgh, said, in his "History of Chemistry," many years ago, that the Hollanduses give very clear descriptions of their processes of treating minerals in investigating their composition, and these serve to show that their knowledge was by no means entirely theoretical, or acquired only from books. It is not surprising, then, to have a great investigating pharmacologist come along sometime about the beginning of the fifteenth century, when, according to the best authorities, Basil Valentine was born. From traditions he seems to have had a rather long life, and his years run nearly parallel with his century. His career is a typical example of the personally obscure and intellectually brilliant lives which the old monks lived. Probably in nothing have recent generations been more deceived in historical matters than in their estimation of the intellectual attainments and accomplishment of the old monks. The more that we know of them, not from second-hand authorities, but from their own books and from what they accomplished in art and architecture, in agriculture, in science of all kinds, the more do we realize what busy men they were, and appreciate what genius they often brought to the solution of great problems. We have had much negative pseudo-information brought together with the definite purpose of discrediting monasticism, and now that positive information is gradually being accumulated, it is almost a shock to find how different are the realities of the story of the intellectual life during the Middle Ages from what many writers had pictured them.