BOOK XXXIV. L. 167 ryo 



laid and covered with sulphur and stirred up with 

 an iron spit. While it is being melted, tlie breathing 

 passages should be protected during the operation, 

 otherwise the noxious and deadly vapour of the lead 

 furnace is inhaled : it is hurtful to dogs with special 

 rapidity," but the vapour of all metals is so to flies 

 and gnats, owing to which those aimoyances are not 

 found in mines. 



Some people during the process of smelting mix 

 lead-fihngs with the sulphur, and others use lead 

 acetate ^ in preference to sulphur. Another use of 

 lead is to make a wash — it is employed in medicine — 

 pieces of lead with rainwater added being ground 

 against themselves in leaden mortars till the whole 

 assumes a thick consistency, and then water floating 

 on the top is removed with sponges and the very thick 

 sediment left when dry is divided into tablets. Some 

 people grind up lead fiUngs in this way and some also 

 mix in some lead ore,'^ but others use vinegar, others 

 wine, others grease, others oil of roses. Some prefer 

 to grind the lead with a stone pestle in a stone mortar, 

 and especially one made of Thebes stone,^ and this 

 process produces a drug of a whiter colour. Calcined 

 lead is M-ashed Uke antimony and cadmea.^ It has 

 the property of acting as an astringent and arresting 

 haemorrhage and of promoting cicatrization. It is of 

 the same utility also in medicines for the eyes, 

 especially as preventing their procidence, and for 

 the cavities or excrescences left by ulcers and for 

 fissures of the anus or haemorrhoids and swelhngs of 

 the anus. For these purposes lead lotion is ex- 



<" Cf. XXXIII, 68; XXXIV, 106; XXXVI, 63, 157. 

 • See XXXIII, 103 ; XXXIV, 100-104. 



249 

 VOL. IX. I 



