216 PLINY'S NATURAL HISTORY. [Hook XXXIV. 



and the Oleastrensian. 11 * There is no difference whatever in 

 them, when the scoria has been carefully removed hy calcina- 

 tion. It is a marvellous fact, that these mines, and these only, 

 when they have been abandoned for some time, become re- 

 plenished, and are more prolific than before. This would 

 appear to be effected by the air, infusing itself at liberty 

 through the open orifices, just as some women become more 

 prulilic after abortion. This was lately found to be the case 

 with the Santarensian mine in BaHica; 13 which, after being 

 funned at an annual rental of two hundred thousand denarii, 

 and then abandoned, is now rented at two hundred and lifty- 

 five thousand per annum. In the same manner, the Antpnian 

 mine in the same province has had the rent raised to four 

 hundred thousand sesterces per annum. 



It is a remarkable fact, that if we pour water into a vessel 

 of load, it will not melt; but that if we throw into the water 

 a pebble or a copper quadrans, 14 the vessel will be penetrated 

 by the fire. 



CHAP. 50. (18.) FIFTEEN REMEDIES DERIVED FROM LEAD. 



Lead is used in medicine, without any addition, for the 

 removal of scars ; if it is applied, too, in plates, to the region of 

 the loins and kidneys, in consequence of its cold nature it will 

 restrain the venereal passions, and put an end to libidinous 

 dreams at night, attended with spontaneous emissions, and as- 

 suming all the form of a disease. The orator Calvus, it is said, 

 eiiected a cure for himself by means of these plates, and so pre- 

 served his bodily energies for labour and study. The Emperor 

 X CTO i;> r so the gods willed it could never siug to the lull 

 pitch of his voice, unless he had a plate of lead upon his chest; 

 thus showing us one method of preserving tbe voice. 15 Por 

 medicinal purposes the lead is melted in earthen vessels ; a layer 

 of finely powdered sulphur being placed beneath, very thin 

 plates of lead are laid upon it, and are then covered with a 

 mixture of sulphur and iron. While it is being melted, all 

 the apertures in the vessel should be closed, otherwise a 



See B. iii c 12. 



13 Not in Bretica, as Brotero remarks, but in Lusitania, or Portugal ; 

 the modern Santarera. B. 1A See Introduction to Vol. III. 



15 This circumstance is mentioned by Suetonius, c. 20. B. 



