1826.] Royal Institution. 453 



of Pearls ; by Sir E. Home, Bart. VPRS. It is stated, in this 

 communication, that pearls originate in the blighted ova of the 

 shell-fish that produce them, and that they afterwards receive a 

 coat of nakei", when the interior of the shell receives its annual 

 supply. 



The reading was commenced, of a paper. On the Burrovi^ing 

 and Boring Marine Animals ; by Edward Osier, Esq ; commu- 

 nicated by L. W. Dillwyn, Esq. FRS. ; and the Society then 

 adjourned to the 26th of May. 



PUOCEEDINGS OF THE ROYAL INSTITUTION OF GREAT 

 BRITAIN, AT THE FRIDAY-EVENING MEETINGS. 



April 28. — Mr. S. Solly read a paper, on the Porphyry of 

 Christiania, illustrated by a numerous and curious collection of 

 specimens, from Professor Esmarck, and by drawings and 

 engravings. 



Mr. Jopling exhibited and explained in the library, his Sep- 

 tenary system of lines, produced by continuous motion. He 

 showed the use of the instruments which had been constructed, 

 for the application of the system to useful purposes. 



Mr. Clowes sent a set of types, plates, and impressions, 

 relative to his method of printing music in type. The printed 

 sheets were very clear and correct; and it is in these two points 

 that the advantage of the plan consists. 



May 5. — Mr. Faraday explained in the lecture-room, the 

 investigations of Mr. Hennel and himself respecting the sulpho- 

 vinic and sulpho-napthalic acids, and of their salts ; the peculiar 

 powers of hydro-carbon in these compounds was pointed out, 

 and the methods of obtaining the acids ; their characters being* 

 at the same time illustrated. 



On the library-table lay Mr. Perkins's book of patterns, 

 produced by eccentric-lathe-turning, and one of his steel plates 

 and rollers. 



May 12. — The subject of the evening was Lieut. Drura- 

 mond's Station Light, an account of which has been read before 

 the Royal Society ; to our report of which we refer. Mr. Fa- 

 raday explained the nature and particular points of the appli- 

 cation, from the lecture-table, and then the light was shown in 

 the reading-room, and compared with that of an Argand lamp, 

 both being placed in parabolic mirrors. Mr. Drummond's light 

 immensely surpassed in brilliancy the Argand lamp. 



May 19. — Mr. Turrell entered into the history of steel en- 

 graving, and described the various processes by which steel 

 was prepared for the engraving; the precautions in decarbonizing 

 and carbonizing it, in hardening and softening it, were stated; 

 and the way was prepared for the process of engraving on steel, 

 to be explained some other evening. 



Mr, Ritchie, of Nain, brought forward two of his new and 

 ingenious photometers ; and Mr. Howship produced an in- 



