62 DR. LAUDER LINDSAY ON CHEMICAL REACTION 



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YII. The results of experiment on the small scale furnish no 

 index or guide to commercial utility. My own early experiments 

 satisfied me of this ; and my impressions have been confirmed by 

 inquiry made subsequently, both in France and England. Im- 

 porters of orchella-weed and archil-manufacturers have not yet 

 succeeded in discovering any chemical means* short of manu- 

 facture on the large scale, of estimating the different colorific 

 value of the same species. And yet we find lichenological systema- 

 tists (classifiers, and describers of so-called species) confidently 

 professing to accomplish what all the experience of chemists and 

 manufacturers throughout the world has hitherto failed to efiect ! 

 VIII. My results are, on the whole, negative^ so far as concerns 

 my ability to confirm the confident assertions of Ny lander and 

 Leighton anent tlae value of chemical reaction as an absolute or 

 corroborative " character" in botanical diagnosis. Nevertheless 

 the relative experiments and inquiry eliminate many facts of a 

 positive kind in regard to the colorific reactions and properties 

 of Lichens — a subject, I am convinced, which is far from bemg 

 thoroughly known to, or understood by, either lichenologists or 

 chemists. Inter alia, unlooked-for results occasionally occur m 

 species supposed to be devoid of colorific value or properties; 

 while in other lichens, which are used on the large scale in do- 

 mestic dyeing or in commercial dye-manufacture, the results are 

 strangely negative, contradictory, or insignificant. 



On the whole, I am disposed to apply, to the so-called " Cri- 

 teria '* whose value has been the subject of the foregoing inquiry, 

 what Blumenbach is reported to have first said of phrenology, 

 but which has, no doubt, been applied to very many and very dif- 

 ferent subjects in science, both before and since his time: 

 " There is much in it that is new, and much that is true ; but 

 what is true is not netv^ and what is new is not true.'^ Not only 

 are Nylander's and Leighton*s observations not confirmed by the 

 repetition of then* experiments by other authorities ; but I believe 

 it is mpossible to obtain the results they so confidently promise 

 by any single '' character," whether chemical or morphological, or, 

 indeed, in many cases at least, by any combination of characters ! 

 The papers of these distinguished lichenologists appear to me to 

 illustrate the danger of hyperenthusiasm in matters of science 

 (which are, or ought to be, strictly matters of fact), and the 

 aptitude of even the most experienced observers to be misled by 

 a false scent, by a hobby, or a theory. 



