1815.] to Mr. R. Phillip's Animadversions. 293 



previously detected and exposed by you. To be ignorant is un- 

 questionably a misfortune ; but he is surely less censurable who is 

 unacquainted with one fact, stated by only one author, than he 

 who, ignorant of many discoveries, related by several writers, 

 denies them the credit of priority, and claims it for himself: the 

 former is my case, the latter Mr, Hume's; when candour has done 

 its utmost in allowing him the plea of ignorance. 



To your decision, however, Mr. Hume says that he assented 

 long ago ; but so silent has been his admission of what he could no 

 longer deny, that even his friends appear not to have known of this 

 sacrifice of fame to truth : for Mr. Parkes, who long " has been 

 even personally acquainted with" Mr. Hume, has admitted his 

 claim to the discovery alluded to, in the last edition of the Chemical 

 Catechism ; a work deservedly popular, and with which Mr. Hume 

 cannot be unacquainted. 



1 am " equally unfortunate," according to Mr. Hume, " in the 

 two experiments quoted from M. Sage; and have drawn inferences 

 diametrically opposite to those of all the chemists who have written 

 on the subject, especially those of France." If my inferences are 

 just, it matters not from whom I differ; and it would have been 

 more to Mr. Hume's advantage, to show my error, than to over- 

 whelm me with a pretended host of opposing authorities ; I say 

 pretended, for I confidently challenge him to produce the names of 

 those chemists, who have drawn from M. Sage's experiments in- 

 ferences diametrically opposite to mine. M. Sage says " Nitrous 

 acid of 32 degrees occasions at first a brisk effervescence with 

 aerated heavy spar; the nitre which results, requiring much water 

 for its solution, precipitates as soon as it is formed." " (se precipite 

 aussitot qu'il sc forme.)" Now the inference which [ drew from 

 this experiment, is " that nitrate of barytcs is perfectly insoluble 

 in nitrous acid of tlie usual specific gravity ;" to copy the terms in 

 which Mr. Hume has claimed priority of discovery, but omitting 

 indeed the words in which he speaks of an insoluble solution ; a 

 thing much beyond my comprehension, and to the discovery of 

 which I suppose he will be allowed an uncontested rigiit. 



The other experiment quoted from Sage, is, that " marine acid 

 dissolves aerated heavy spar with effervescence, the salt whicli re- 

 sults precipitates immediately. The supernatant marine acid does 

 not hold in solution (nc tient point en dissolution) any salt with a 

 i)asc of heavy earth." The fact expressed in the quotation with a 

 precision that no sophistry can evade, and claimed by JNlr. Hume 

 as his own discovery, is " that muriate of barytcs is virtually in- 

 soIuIjIc in muriatic add." 



This appears to me the plain statement of the controversy; but 

 Mr. Hume has attempted to elude these deductions by a truly 

 notable expedient ; for it is one which, if it succeed in supplying 

 his present pur|)05e, nujst ii)evitai)ly deprive him of the jiriority of 

 the two discoveries remaining out of .'<evet), wliich he has claimed 

 in his paper on barytcs, in ISOJ. Mr. Ihiine asserts that in Sage's 

 txpcriuients, " there is neither water of solution nor water of crys- 



