DYE-STUFFS USED IN ITALY. 211 



Castelnuovo, Catania, in Sicily, Aquila in the Capitanata, St. Gavino in 

 Sardinia, Bibbiena, and Montalcino in Tuscany. 



The seeds of Avignon (Rhamnus cathartica) are very plentiful in the 

 Maremmas, and are used to dye the skins yellow, or green when they are 

 mixed with indigo. 



Fustic {Madura tinctoria) is employed for similar purposes as those 

 of the roots of the berberry tree, but it does not give so deep a colour. 

 The best comes from Cuba. 



Quercitron, or the bark of the Quercus tinctoria, might be used 

 in the same manner as sumach. If this kind of oak were more culti- 

 vated, it Avould be very useful in the tanning business. 



The green ebony from the Antilles {Excozcaria glandulosa) or 

 Jacaranda avalifolia, has been used with success in some of our dyeing 

 works, but at present is not much known. 



For a description of the sulphur yellow ebony of Guiana, or Taigu of 

 Paraguay, or Tpe of Brazil and Uruguay, the Olombeire of the Indian 

 colonies of Portugal, see the paper which I presented, in 1858, to the 

 Academy of Sciences at Paris. 



Respecting the yellow bark of Australia, see a second treatise, pub- 

 lished by me in June, 1857. If Australia sent us any great quantity 

 our dye works would be able to employ it largely for the purpose of giv- 

 ing sheep skins and stuffs a deep yellow colour, produced by an alkaloid 

 similar to that of the berberry tree. 



"We may also mention various sorts of wood coming from Siam and 

 Australia, and among them the Ouan-disi of China, Gardenia sp. 



Picric acid, which is made at Turin and Milan, by the action of nitric 

 acid upon indigo and coal tar, is obtained by the distillation of the 

 bitumen of coal (phenic acid). 



With regard to the prodtiction of blue colour. Amongst the matters 

 employed by dyers, there is Prussian blue, obtained by the reaction of 

 a salt of iron with soda and prussiate of potash. The blue colour of the 

 indigo is produced in a large tub, either by a cold process with woad, or 

 by dissolving indigo in sulphuric acid. Azuline is not used because of 

 its high price. Indigo, lime, and sulphate of iron, are also used. 



The red colouring matters come next in order, and are as follows : — 

 Madder (Rubia tinctoria) has for a long time been used in the dyeing of 

 skins. The best comes from the plains of Capaccio, the neighbourhood 

 of Salerno, Naples, and the Tuscan Maremmas, where it has been culti- 

 vated for many centuries. At present, Brazil wood and cochineal are 

 used for the same purposes. Attempts have been made to rear cochineal 

 in the kingdom of Sardinia, with not very satisfactory results ; some 

 small quantity is produced in Sicily. 



The berries of the Phytolacca decandra are used for dyeing purple and 

 violet the skins prepared with sumach, and the sheepskins of Florence. 

 The preparation and the use of the orchella (Rocella tinctoria and Rocella 

 fusiformis, Variolaria orcina, and V. dealbata, Lecanora, &c), has been 



