ON THE BORACIC ACID OF CENTRAL ITALY. 



297 



evaporators, by steam passing through an underground chamber. The 

 boracic acid being spread out in thin layers on the floor, is stirred from 

 time to time with a wooden rake, and the crystals, while losing their 

 sharp angles, separate in great measure from each other. When dry 

 nothing remains to be done but to shovel up the mass of crystals and 

 remove them to the warehouse, where the produce of all the establish- 

 ments is mixed, to ensure its being all of uniform quality. It is then 

 put in large barrels, containing 2,000 Tuscan lbs., or 13^ cwt., and con- 

 veyed to Leghorn, whence the greater portion is exported to England. 



The first impression produced on my mind, when I first went through 

 the establishment, was the marvellous simplicity of the successive 

 processes, almost everything being performed by Nature : little has to 

 be affected by human agency but to convey water to the lagoni and re- 

 gulate the supply in the various operations, to empty the barrels and 

 spread out the crystals on the floor to dry. Such is the work allotted to 

 the 40 men who are employed at Lardarello on ordinary occasions. 

 They commence at four a.m. in summer, and at sun-rise in winter, and 

 only work on an average four or Jive hours daily : thus I arrived at ten 

 a.m., but they had finished tor the day ! The art of procuring boracic 

 acid is, however, very harassing ; sometimes the sides of a lagoon break 

 in, or there is not sufficient water ; perhaps through carelessness on the 

 part of the men the steam supply diminishes at a particular spot, as is 

 liable to occur, unless they regulate the quantity of water accordingly ; 

 the inevitable consequence is that the lagoon becomes useless, and the 

 steam seeks an easier vent for itself elsewhere. In some cases it forms 

 a new soffione a hundred yards off, or else, unable to force an immediate 

 passage to the surface, it is necessary to have recourse to boring, and a 

 perfectly new lagoon is constructed. This ojjeration is by no means an 

 enviable task ; the ground feels so hot near fissures which do not quite 

 reach the surface, but from which steam issues out in minute jets, that 

 one's feet are scorched through a very thick pair of shoes, and one is 

 warned to retreat, since a few steps further on would probably cause a per- 

 son to sink into a hidden cauldron, or steam-bath. Around this place are 

 fragments of alberese limestone, the gradual metamorphoses of which are 

 very visible ; first the rock, which has a dirty-brown discolouration, is 

 shivered and rendered friable, and in other places absolutely converted 

 into gypsum, as has been described by Savi and Meneghini ; besides 

 these there are clays and marls of the Eocene, Miocene, and Pleiocene 

 formations. 



Produce op Boracic Acid from Count Lardarel's Lagoons. 



From Tons.cwts. 



1818 to 1828 (ten years) 521 16 

 1829 to 1838 (ten years) 4,870 6 



1839 948 13 



1840 878 13 



1841 886 6 



1842 

 1843 

 1844 

 1845 

 1846 



Tons. cwts. 

 . 923 15 

 . 923 16 

 . 923 16 

 . 923 15 

 . 1,043 13 



