LICITEX-rLORA OF ]S'OnTIIEE^^ ErEOPE. ' 415 



A 



red dyes, and in contrast with tliem tlie same species from IVeiv 

 Zealand, India, and other parts of the world, in order to determine 

 approximately and roughly how far climatic and other differences 

 aflect their colorific property. The northern lichens experimented 

 on were mostly : 



1. Lecanoj^a iartarea^ Ach. 



2. L, par ella, Ach, 



3. Parmelia sascatilis, Ach. 



4. Umhilicaria erosa^ Hffm, 



5. Samalina scopitlortim^ Ach. 



The general result was, that the same colour, with certain differ- 

 ences in quality or intensity, was yielded in all cases hy the same 

 species, from whatever country derived, the circumstances of ex- 

 periment being virtually the same in all. Such results, however, 

 of experiments conducted on the small scale cannot he in all senses 

 relied on. They appear, for instance, opposed to the fact that 

 orchil-manufacturers are guided by their experience to prefer 

 ^ " orehella weed '' (species of BoccelJa) from equatorial or subequa- 

 torial maritime regions ; under which circumstances of growth the 

 same species is found to be richer in colouring-matter than when 

 it IS collected from higher latitudes and more inland localities. 

 As the result of all my inquiries and experiments on the subject 

 since 1850, I have little doubt that latitude, climate, temperature, 

 moisture, exposure, elevation, geological character of the soil, 

 nature of the trees on which they grow, and in general all those 

 conditions which affect the botanical character of the plant (and 

 the genus Bocella is one of the most variable in the whole liclien- 

 family) also affect their chemical character, and so render the 

 SocceUcG more or less serviceable for the purposes of the colour- 

 manufacturer or dyer. 



It is here worthy of remark that the natives of tropical or sub- 

 tropical countries which abound in valuable dye-lichens, who 

 export them largely for the European market, are yet themselves 

 Ignorant of their uses and value. For instance, my friend Dr. Kirk 

 informs me that large quantities of certain corticolous maritime 

 Soccellce (probably B. Montagnei, Del., or various forms of E./uci- 

 formis, Ach,, to which I am disposed to refer i?. Montagnei as a 

 variety) are exported regularly from Zanzibar, Eastern Africa, 

 partly via Bombay, but in great measure directly to Portugal and 

 Trance. These are by far the most valuable dye-lichens known, 

 and they have gradually supplanted, in the British market at least, 

 all other species and genera. Yet, says Dr. Kirk, they are un- 



