CORRESPONDENCE OP RAY. 167 



Dr. Robinson to Mr. Ray. 



Sir, — As for the transmutation of secondary principles, 

 or elements, one into another, I was tempted to believe 

 it practicable, upon discom'sing several times with Mr. 

 Boyle upon that subject, and upon reading his new 

 Appendixes to the ' Sceptical Chemist,' and to the ' Aery 

 and Icy Noctiluca,' where he affirms that oils and water 

 may be wholly changed into earth, though never so well 

 purified before ; and that salt and sulphm^ are trans- 

 mutable into insipid water, which also Tachenius demon- 

 strates, and salt into earth ; and this not by the 

 addition of any new parts, but by mere transposition, 

 division, or some new modification of the constituent 

 parts, which, making a difierent impression upon our 

 senses, may produce new qualities or accidents ; but you, 

 being a much greater master of the Epicurean philosophy 

 than myself, are the best judge of this. I always fancied 

 that there were no fixed or immutable principles (I mean 

 elements) in nature, as she stands at present, but what 

 may be subject to changes upon new motions, or modifi- 

 cations, unless we suppose pure atoms without concre- 

 tions, and them too under the same constant laws of 

 motion. I grant that salt, water, or any other purified 

 element, may contain many corpuscles of the same kind ; 

 yet these same particles, by various transpositions, di- 

 visions, motions, or any other new modifications, may 

 put on difierent faces and shapes, and raise in us various 

 perceptions of difierent qualities and accidents. If this 

 philosophy be true, then fixed salts themselves may differ 

 from each other in sensible qualities, or accidents, ac- 

 cording to the operations or other circumstances, though 

 they be carefully purified. Mr. Lewenhoeck hath ob- 

 served great variety of figures in them after they had 

 been diligently freed from adhering heterogeneous par- 

 ticles ; and the very same numerical lixivial salt will put 

 on different shapes and figures, so that it will appear a 



