在现代化学科学出现之前的几千年里，人类一直在探寻物质变化现象的奥秘。那时人们将这些变化现象视为属灵真理的启示，基于它们建立天地万物的理论（还有很多自然界根本不存在的东西），并将它们运用于制造器物、艺术品和手工制品，其中最为特别的一项应用是不死药的制造，一种令人痴迷却从未开花结果的巫术——炼金术. 化学，是一门研究物质变化规律的科学，它强调知识的准确性与系统性。我们可以将炼金术描述为一种肤浅的、主观随意的考察，以及建立在这种基础之上的理论系统，其全然是凭空想象的艺术创造。 根据古老的文字记载，亚当是第一位炼金术士。据说亚当是在第六天被创造出来的，即世界始创第一年的三月十五号。毫无疑问，炼金术存世已久，而化学一直到18世纪中叶才诞生。 从未有一个科学的分支像化学这样有如此之长的潜伏期。一种物质如何能够生成为另外一种完全不同的全新物质？人类在解密这一现象的过程中，肯定存在着极大的困难。 先人对于世界的看法绝然迥异于现代人，探究这些博学广识的古代先贤们对于物质变化现象的见解，将是一件有趣的事情，而且肯定也是大有裨益的。 如果翻阅现代化学著作（比如，这个系列里的《化学元素的故事》），读者将会发现，著作的开头，化学家们只是粗浅地描述了那些他们研究领域里的特殊现象，而关于它们的解释也只有部分涉及到化学领域。然后他们才详细展开阐述那些发生于自然界中的或可以进行控制性实验的类似现象。同时引导读者如何看到这些变化之间的相似点，如何理解化学事件，如何找出它们的异同。渐渐地，读者可以摸索着找到一般性的总结，一种可以适用于绝大多数化学过程的严格准确的表述。最后，读者将发现，一些完整确切的成形归纳适用于各种化学变化情况。但是，如果我们转向炼金术士的著作，你会发现一个完全不同的世界。这与人们在现代化学书上感受到的完全不一样。 For thousands of years before men had any accurate and exact knowledge of the changes of material things, they had thought about these changes, regarded them as revelations of spiritual truths, built on them theories of things in heaven and earth (and a good many things in neither), and used them in manufactures, arts, and handicrafts, especially in one very curious manufacture wherein not the thousandth fragment of a grain of the finished article was ever produced. The accurate and systematic study of the changes which material things undergo is called chemistry; we may, perhaps, describe alchemy as the superficial, and what may be called subjective, examination of these changes, and the speculative systems, and imaginary arts and manufactures, founded on that examination. We are assured by many old writers that Adam was the first alchemist, and we are told by one of the initiated that Adam was createdon the sixth day, being the 15th of March, of the first year of the world; certainly alchemy had a long life, for chemistry did not begin until about the middle of the 18th century. No branch of science has had so long a period of incubation as chemistry. There must be some extraordinary difficulty in the way of disentangling the steps of those changes wherein substances of one kind are produced from substances totally unlike them. To inquire how those of acute intellects and much learning regarded such occurrences in the times when man's outlook on the world was very different from what it is now, ought to be interesting, and the results of that inquiry must surely be instructive. If the reader turns to a modern book on chemistry (for instance,The Story of the Chemical Elements, in this series), he will find, at first, superficial descriptions of special instances of those occurrences which are the subject of the chemist's study; he will learn that only certain parts of such events are dealt with in chemistry; more accurate descriptions will then be given of changes which occur in nature, or can be produced by altering the ordinary conditions, and the reader will be taught to see certain points of likeness between these changes; he will be shown how to disentangle chemical occurrences, to find their similarities and differences; and, gradually, he will feel his way to general statements, which are more or less rigorous and accurate expressions of what holds good in a large number of chemicalprocesses; finally, he will discover that some generalisations have been made which are exact and completely accurate descriptions applicable to every case of chemical change. But if we turn to the writings of the alchemists, we are in a different world. There is nothing even remotely resembling what one finds in a modern book on chemistry.