_Test_ is an alchemist’s word, coming from the Latin ‘testa’, an earthen pot in which the alchemist made his alloys. The same word was once used as a slang term for ‘head’, and in its French form, ‘tête’, still retains that meaning. The phrase _hermetically sealed_ reminds us that alchemy, known as the ‘hermetic art’, was traced back by its exponents to the mysterious Hermes Trismegistus, who himself took his name from the Greek messenger-god Hermes. Other alchemists’ words are _amalgam_, _alcohol_, _alembic_, _alkali_, _arsenic_, and _tartar_. The last five, together with the word _alchemy_ itself, all come to us from Arabic, and are evidence of the fact that the Arabs of the Dark Ages, besides being philosophers, were the fathers of modern chemistry. It was, indeed, they who first joined the study of chemistry to the practice of medicine, and thus initiated a science of drugs. Moreover, that old ‘humoral’ pathology which has shaped so many of our conceptions of human character—in so far as it was based on ancient authority and tradition—came from Hippocrates to Europe, for the most part not directly, but by way of Baghdad and Spain. The more intimate and indispensable such conceptions are, the more effort does it require from the twentieth-century imagination to realize how they have grown up. It is so difficult, even when we are reading contemporary literature, to blot out from our consciousness the different meanings which have since gathered round the words. If, however, we can succeed in doing this, we cannot but be struck by the odd nature of the change which they have all undergone. When we reflect on the history of such notions as _humour_, _influence_, _melancholy_, _temper_, and the rest, it seems for the moment as though some invisible sorcerer had been conjuring them all inside ourselves—sucking them away from the planets, away from the outside world, away from our own warm flesh and blood, down into the shadowy realm of thoughts and feelings. There they still repose; astrology has changed to astronomy; alchemy to chemistry; to-day the cold stars glitter unapproachable overhead, and with a naïve detachment mind watches matter moving incomprehensibly in the void. At last, after four centuries, thought has shaken herself free. CHAPTER VIII EXPERIMENT _Zenith._ _Law._ _Investigate._ _Conceit._ _Gentleman._ _Love._ _Protestant._