94 Chemical Pldlosopliy. [Chap. IL 



others, were composed of particles which had the 

 fomi of wedges or hooks ; that solution consisted 

 in the insinuation of these wedges or hooks, be- 

 tween the particles of the bodies to be dissolved ; 

 and that chemical combination was merely the 

 linking of the different particles together, by means 

 of holes in one set of them, into which the hooks 

 or the wedges of the other set were thrust. Such 

 explanations, absurd as tJiey may appear, were 

 generally fashionable, until Newton ftrst ascribed 

 the chemical union of bodies to an attraction be- 

 tween the particles themselves : a doctrine which 

 was soon unanimously received, and has continued 

 ever since to prevail. The nature and laws of this 

 attraction were afterwards better explained and 

 systematised by Mr. Geoffroy, a philosopher of 

 France, who invented a method of representing the 

 different chemical affmities by figures and diagrams, 

 and arranging them in tables ; a method which has 

 since been generally received into practice, and 

 greatly contributed to the facility and advancement 

 of this science. 



■ Contemporary with Geoffrey was Boerhaave, 

 who, among the various objects to which he direct- 

 ed his great and excellent mind, gendered himself 

 conspicuous by his attention to chemistry. He 

 made many new experiments, and improved almost 

 ^very part of chemical philosophy which was then 

 known. He was particidarly distinguished by 

 maintaining, in opposition to Boyle and Newton, 

 that heat was a real specific substance, a fluid uni- 

 versally diffused, and one of the most important 

 agents in nature. In supporting this doctrine he 

 triumphed over his illustrious opponents, and esta- 



