Pkitina and Mercury upon each other. m 



But, even if attended with complete j^uccess, there is a che- 

 inieal reason which must nialce us refuse our assent to this 

 estimate. It is possible, and not unlikely, that a portion 

 ot" mercury may be retained in solution by the platina, as 

 well as that a portion of the platina may be precipitated by 

 means of the mercury. The mean result, however, was 

 that the precipitate by green sulphate of iron consisted of 

 about 17 of mercury and S3 of pbtiaa, when the specific 

 gravity was about 1 6. 



With regard to palladium, lest it should be supposed that 

 either my own observations or those of others liave fiven 

 me cause to alter mv opinion. I w ill add, that I have as 

 ■yet seen no arguments of sufficie;it weight to convince me, 

 in opposition to experiment, thai palladium is a simple sub- 

 stance. Repeated failure in the attempt to form it, I am 

 too well accustomed to, not to believe that it may happen 

 in well conducted operations ; but four successful trials, 

 which were not performed in secret, are in mv mind a suf- 

 ficient answer to th^at objection. Bv determining the pre- 

 sent question we may overcome the prepossession conceived 

 by many against the possibility of rendering mercury as' 

 fixed, at an elevated temperature, as other metals ; we mav 

 be led to see no greater miracle in this compound than in 

 a metalHc oxide, or !n water, ?.nd be conipelicd to take a 

 middle path, between the visions of alchemy on the one 

 handj and the equally unphilosophical prejudices on the 

 other, which they are likely to create. In the course of 

 experiments just now related, I have seen nothing but what 

 tetids to confirm my former results; yet the only means 

 which I can, after all, prescribe for succeedir.g, is perse- 

 verance. 



To ascertain whether the opinion of Messrs. Fourcrov 

 and Vauquelin, that the new metal was the principal in- 

 gredient in palladium, had any just foundation, 1 observed 

 the methods they have recommended for obtainino- pure 

 platina ; but I did not perceive any difference in the facility 

 with which either kind of platina combined with mercurv. 



I mitrht have added some more experiments to corrobo- 

 rate the evidence I have adduced to prove my assertion of 

 the fixation of incrcury by platina; but Messrs. Vauquelin 

 and Fourcroy have promised the Institute of France a con- 

 tinuation of their researches, and M. Riciiter concludes his 

 pa|)er with saying that he will return to the subject. From 

 the labours vf such persons some great and important fact 

 must issue, and 1 ho|)e that ihe present subject will not be 

 excluded from their consideration. The facts contained in 

 7 this 



