\ Bel Thesry of the Earthy 73g 
3 and folubility *. | “If this defeription is well’ drawn up, the 
érror. refpeting the name may be rectified, and the obfervas 
~ tion will not be loft, a$ it ‘would be were there any reafon to 
 fiifpeét the juftnels of the’denomination, and no means of cér- 
reGting i it by a defeription f. ’ 
* 16. When the characters of a foflil give it facha hkenefs 
to another that it is found near the limits which'{e sparate the 
_ Senera or fpecies of thefe' two foffils, we' mutt follow’ the ex- 
_ ample of Werner and his difciples}:by marking: that this fof- 
- filis intermediary, or forms a tranfition from the one fpecies 
| to the other. For if we fhould afcrile™it- exclutively-to the 
enus A, without noting the characters which bri ring it.near 
to the genus B, another obferver, on feeing the Bins fofil, 
“might refer it to the genus B, and no one koala Kiiow which 
of them was déccived. 
-, 17- People are often deceived alfo by mixing opinion with 
obfervation, and giving the former for the latter ; as when 
- people affert, that they have feen veftiges of extinguifhed vol- 
canoes, » Dbecautle: they have feen black or porous. ftones, or 
§ ‘ftones of a prifmatic form, without deigning to deferibe t them 
ge care, but by qualifying them. merely as lava‘ or ale 
. 186 In the laft place, a very frequent fouree of e1 error o 
ereat a confidence ‘in the fi fidelity of one’s memory or in oe 
; julinefs of one’s firft obfervations. Thee two ii of con- 
fidence go often hand in hand; and people éannot BR? ard 
-againft the errors, which are the confequence of them, but 
“by noting down, on-the fpot, :all: obfervations to witch jany 
‘importance is attached, cfpecially if they are a\litthe complex, 
and carry away fpecimens, with ‘their characters earefitll+ 
“marked upon them, of the objects that ‘are the fubject of 
a ‘Hardnefs, refrangibilitv, eleétricity, &ce HH. ; 
gsSaul A perfon now dead, who in h’s time was confidered as a unlidgis 
_ it, } Wrote ‘to me that he had found marine fhells in'pranites Iebegged 
jim to give mevan exa€t defeription of: the fione which he calledspraniie, 
He ait fo; but E perceived that the {tone was a free- ftone ov fand-ftonéyand 
7 € fpecinens he wfterwards fent me proved that [was not deceived. 7 Wie 
ix 4y here recollect Reeupero’s pyrites of Altna.) The errors of thiskind, 
rifing from falfe denominations, are innumerable ;: foranexaét know- 
UA a of inineral fubhiahces is more difficult to be obtained, and more raré,, 
7 an is generally nnagined;—Note of the Auruomy: (41 4 | 
a i Te thefe 
