100 rRETENDED KEW METAL; PALLADIUM, 



fhould produce a mafs of the fpecific gravity of 10,972 ; not 

 much more than half of that which calculation would denote. 

 Other fimilar and inferior to either of its elements. In Mr. Hatchett's Pa- 

 per upon the Alloys of Gold, to which I always refer with 

 pleafure, we find fome extraordinary inftancesof anomalies in 

 fpecific gravity, both in excefs and diminution upon the cal- 

 culated mean. His experiments have not been doubted ; nor 

 can their accuracy be called in queftion. The principle of de- 

 viation in the true and the calculated mean is therefore ad- 

 mitted. Who then can fay where this deviation Ihall end, or 

 mark out limits to the operations of nature ? 

 Particularly the But a no lefs extraordinary inflance of irregular denfity is 

 difFerent Specific j^j, ^j^fy^e our eyes ; yet it has not fo much as attraaed our 

 gravities of •/. t-,-.i/. , r 



gafifornr water attention. It IS true that it is taken from among the gafes, 

 or fteamand a g^j^^ jf ^^ fuppofe that we have attained accuracy in experi- 

 gafes which ments upon thefe fubjeds, I fee no reafon to refufe their evi- 

 form it. Thefe dence in this inftancc. The denfity of oxygen gas, to that of 

 arc as 7 4. ^j^fgj, jg ^^ | jq 740; and the denfity of hydrogen gas as J to 

 9792. The mean denfity of that proportion of oxygen and 

 hydrogen gafes which confiitutes water, is to that of water as 

 1 to 2098; or, in other words, water is 2098 times heavier 

 than the mean denfity of its elements in the gafeous fiate. But 

 water is only 1200 times heavier than fleam, or water in the 

 fiate of vapour. Therefore, there is a variation in -\-, of 898, 

 or nearly half, between the denfity of water and its elements, 

 when both are in the aeriform ftate. This fad, however, re- 

 gards bodies only as they. remain in the fame ftate, whether of 

 folidity, liquidity, or fluidity. The anomaly is mnch greater, 

 if we contemplate them as they pafs from one of thefe ftates 

 to the other. Yet we muft not omit the confideration of fuch 

 a change, in the inftance of mercury alloyed with platina ; for 

 the former metal, before liquid, becomes folid as it enters into 

 the new combination. 

 The fixation of ^ ftronger prejudice will perhaps exifl againft the fixation 

 mercury is a fad of fo volatile a fubflance as mercury. It is certain that the 

 inan*^others laboAirs of the alchemifis have thrown fome ridicule upon this 

 and ought to fubjeft, as a philofophicial purfuil. Men of fcience have long 

 excite no preju- fj,,(_.e declined the refearch ; and it is not probable that we are 

 indebted to experiments undertaken in the true fpirit of phi- 

 lofophy, for the prefent fixation of mercury. But, the fame 

 caufe which induced us to look upon the projefl as chimerical,- 

 4 Ihould 



