CLAIMS or LAVOISIER. 235 



observation ;^ it only aids its deficiencies, corrects its errors, or 

 hastens its results: and it is surely of but little importance, 

 5.vhetlier the experiment be conducted by the spontaneous 

 movements of nature, or by putting her to the torture, as Ba- 

 con says, by the efforts of human ingenuity, provided the ob- 

 servation of its plienomena be equally exact and the concia* 

 sion be with equal accuracy obtained. But in truth, Rey did 

 make experiments; for what was the burning of a metal in a 

 vessel but making an experiment ; and what was the conclu- 

 sion he drew, contrary to the opinion of preceding authors, 

 but the result of a sagacious observation of the phenomena 

 which that experiment exhibited? He went half way in th« 

 discovery of oxidaiion ; and Dr. Hales completed it, by shew- 

 ing that the condensed air was again liberated by heat. M. 

 Lavoisier's claims go no farther than having ascertained the 

 facts with greater accuracy, and rendered them of more ex- 

 tensive application. 



With regard to the theory of acidification, the claims of M. The theory of 



Lavoisier are not much better founded ; for the following aci^ifjcaton is 



' o stated with 



circumstances will shew that others divide with him that considerable 



honour. Mayow long ago proved that nitre consisted of an Mavow^and ^ 

 alkaline salt derived from the earth, and of an acid spirit, an cf the earlier 

 tliat the contact of air with the soil was essential to its ^ ^^^^ ^' 

 production.* At first he considered the acid spirit to 

 be derived wholly from the air, but afterwards from its 

 great density, held that only its more active part was ob- 

 tained from that source.f Boyle having proved that some- 

 thing essential to combustion existed in the air, Mayow called 

 this something the igneous particles of the air, and contended 

 that these same particles existed in nitre ; for that in vacxio 

 sulphur would not burn, but when mixed with nitre, it would 

 burn either in vacuo or under water,| He afterwards con- 

 cludes that the aerial part of nitre is nothing else but these ig- 

 neo-aereal particles, and that they reside not in the alkaline 

 base, but in the acid spirit of the nitre, to which the caustic 

 nature of that spirit is owing. § 



* Tractat. quinq. p. 2 — 4. f Ibid. p. 11. 



X Ibid. p. 13. § Ibid. p. 19. 



Dr. 

 Hh2 



