380 Memoranda on the < Chulchulheera' of the Hills. [No. 113. 



hope to find some equal to, or indentical with these, but we may be 

 well content with the goodly supply of the secondary sorts, with our great 

 extent of territory must insure us when they are known. In no trade is 

 there so much competition and so many secrets as in the dying and print- 

 ing of silks and ottons ; and I take it that none of the published notices 

 give any distinct idea of any thing, as to the value and kinds of lichens, 

 I eyond what is already well known in the business : the secrets are far 

 too valuable to be given away. The colouring principle moreover is not 

 the only part of the lichens to be turned to account, gummy matter, 

 extracted from them by Lord Dundonald's process, supplies the place 

 of the costly gums in many printing processes. 



There is an omission in all the printed notices which I have yet seen, 

 which in many cases might mislead persons testing lichens. An impor- 

 tant process — that of crushing or even pounding the moss or lichen to 

 powder — is wholly omitted ? A chemist would of course think of this j 

 and Hellot, the inventor of the ammoniacal test, from whose writings all 

 have subsequently copied, mentions it ; but the usual directions lead 

 people to suppose that the lichen is merely to be broken to pieces and 

 infused, which may often be insufficient to develope the colour properly, 

 and thus lead to a wrong conclusion. 



The single lichen Rocella has been a mine of wealth to the Canaries 

 and Cape de Verd islands. We have at least a fair chance that India 

 may produce one, if not more, of these productions of a valuable kind, but 

 nothing can be properly ascertained on the subject unless a considerable 

 quantity — say a maund or two of each promising sort — be sent home. 

 In the hands of European dyers and chemists, with their extensive re- 

 sources, great experience, and ample leisure, it is quite possible that results 

 may be obtained, which, our petty means, and want of experience and 

 leisure, are quite unequal to develope. I have, for example, strong reason 

 to believe that some of these lichens contain the ' Erythrine,' or violet-red 

 principle of Heeren and Nees Von Esenbeck ; but the research is one 

 of those in speculative chemistry, which I have neither means nor time 

 to undertake. I shall nevertheless be happy at all times to contribute 

 my mite of aid, whenever it can be useful in the search for good dying 

 lichens. 



