On the conjlitiient Parts of Azof. 555 



fpeaks to him almoft in the fame manner as the inquifitor to 

 Galileo when he endeavoured to prove to that immortal man 

 that the fun moved round the earth. Prieftley then gives ua 

 his own theory on the produftion of organifed azot* The 

 feeds of this plant, he fays, float every where ; in the air, ou 

 the earth, on the fea, on the Alps, in the plains, vmder the 

 poles and the equator, in fummer and winter, and in all 

 feafons, and are received into the water, where they germi- 

 nate : but organifed azot is produced in bottles well corked. 

 Dr. Tngenhouz has even proved, that by filling a bottle with 

 well water, and inverting it in a bafon filled with water, or- 

 ganifed azot is formed in large quantities. Prieftley, who 

 could not maintain, without fuppofing an intelligence fupe- 

 rior to the pretended feeds of this plant, that they had come 

 through the water on purpofe to fettle in this bottle prepared 

 for them, extricates himfelf from his difficulty by making 

 them pafs through the glafs by imperceptible fiflures*. Such 



long ago refjted. The following are his own words ; " conjider'ing bow 

 long the dodrine of eqiti-uocal or fpo>:taneoii$ generation has been exploded.^' 

 A philofopher ought never to make ufe of fuch an exprelfion. There is 

 no refuted opinion to which we mav not recur, and again examine. Phi- 

 lufophy acknowledges no authority which can profcribe it from admitting, 

 or forbid it to examine. There are many other opinions, long ago refuted, 

 to which we ought dill to recur j for example, that of the tranfmutation o£ 

 metals. What chemift at prefent will dare to deny the pofiibility of it > 

 The change of one metal into another ought to appear jefs difficult thaa 

 the converfion of the fweeteft body (fugar) into the foureP- (oxalic acid)i 

 than tlie change of the hardeft body (the diamond) into the fofteft (car- 

 bonic acid gas); than the change of the mofl tranfparent (the diamond) 

 into the mod opake (charcoal). In the i()th century the tranfmutation of 

 metals will be generally known and pra6liled. Every chemift, every anift 

 will make gold ; kitchen utenfils will be of filver, and even gold, whicli 

 will contribute more than any thing elfe to prolong life, poifoned at pre- 

 fent bv the oxyds of copper, lead, and iron, which we daily fwallow vvitU 

 our food. There wriH then be no other riches than natural riches ; the 



produftions of the foil : artificial riches, fuch as gold, lilver, and paper 



money, will vanifti in the hands of thofe who have accumulated them. 



What a revokition in fociety ! Every enlightened chemift, however, will 



agree with me, that this revolution is not only probable, but at no great 



diftance. — Note of the Author. 



* Through fome unperceived frafliire. Vol. III. p. 294. The feeds of 



this plant infmuatc thcmfelves iato vcffels of ».vat«r thryu^li the fmalleft 



apertures, p. 308, 



Vol. VI. Z2 i? 



