86 Dr Bowring on the Boracic Acid Lagoons of Tuscany. 



covered with beautiful crystallizations of sulphur and other 

 minerals. Its character beneath the surface at Mont Cerbole 

 is that of a black marl streaked with chalk, giving it, at a short 

 distance, the appearance of variegated marble. 



Formerly, the place was regarded by the peasants as the en- 

 trance of hell, a superstition derived no doubt from very an- 

 cient times, for the principal of the lagoons and the neighbour- 

 ing volcano still bear the name of Monte Cerboli (Mons Cer- 

 heri). The peasantry never passed by the spot without ter- 

 ror, counting their beads, and praying for the protection of 

 the Vu'gin. 



The borax lagoons have been brought into their present pro- 

 fitable action Avithin a vei'y few years. Scattered over an ex- 

 tensive district, they are become the property of an active in- 

 dividual, M. Larderel, to whom they are a source of wealth, 

 more valuable perhaps, and certainly less capricious, than any 

 mine of silver that Mexico or Peru possesses. The process 

 of manufacture is simple, and is effected by those instruments 

 which the localities themselves present. The soffioni, or va- 

 pours, break forth violently in different parts of the mountain 

 recesses. They only produce boracic acid when they burst 

 with a fierce explosion. In these spots artificial lagoons are 

 formed by the introduction of the mountain streams. The 

 hot vapour keeps the water perpetually in boiling ebullition ; 

 and after it has received its impregnation during twenty-four 

 hours at the most elevated lagoon, the contents are allowed 

 to descend to the second lagoon, where a second impregnation 

 takes place, and then to the third, and so forth, till it reaches 

 the lowest receptacle ; and having thus passed through from 

 six to eight lagoons, it has gathered one-half per cent, of the 

 boracic acid. It is then transferred to the reservoirs, from 

 whence, after a few hours' rest, it is conveyed to the evapora- 

 ting pans, where the hot vapour concentrates the strength of the 

 acid by passing under shallow leaden vessels from the boiling 

 fountains above, which is quite at a heat of 80° of Reaumur*, and 

 is discharged at a heat of 60°-f-. There are from ten to twenty 

 pans, in each of which the concentration becomes greater at 



* The boiliug point. t 167 ' of Fahrenheit. 



