473 
Zinkenite. . . . . S, Pb+S;, Sb. 
Plagionite . . . 4(S, Pb)+3 (S;, Sb). 
Jamesonite . . . [5(S, Pb)+S;, Pb.]+4 (S;, Sb)? 
Featherore oflead 2 (S, Pb)+Ss, Sb. 
Boulangerite . . 3(S, Pb)+S;, Sb. 
A mere inspection of the formule is sufficient to show 
that each mineral in this list is distinct in composition from 
that whose analysis has been given above. There is, however, 
an ore possessing a constitution perfectly analogous to the Irish 
mineral—namely, the sprédglaserz of Mohs and Werner, 
or what Dr. Thomson calls brittle silver glance. The formula 
of this mineral Rose has shown to be 6(S, Ag)+S;, Sb; 
so that it differs from Kilbrickenite merely in containing 
silver instead of lead. 
The following note— On a principle for producing an 
everburning Flame,” by George J. Knox, Esq., was read by 
the Secretary : 
** A beliefin the discovery of an everburning lamp appears 
to have been prevalent in all ages; and tradition informs us 
that lamps have been found in tombs, where they have con- 
tinued burning for upwards of 1000 years, of which mention 
has been made in the works of St. Austin, Plutarch, Pliny, 
Ludovicus Vives, Baptista Porta, and Licetus. The 
Rosecrucians,* who laid claim to the knowledge of every- 
thing mysterious, pretended to have rediscovered the secret 
of their construction, which was supposed to have been 
buried in the tomb of their founder. Dr. Plott,f in a 
treatise which he has written upon this subject, alludes to a 
lamp mentioned by St. Austin in his book de Civitate Dei, 
which was hung up in the temple of Venus; and to another 
found in the tomb of Pallas the Arcadian, who was slain by 
Turnus in the Trojan war, which continued to burn after 
* Spectator, vol. v. No. 379. 
+ Lowthorp’s Abridgment of Phil. Trans, vol. iii. (636). 
