Church. — On the Chemistry of Phormium tenax. 269 



It will be seen that in all the series no appreciable advantage was gained 

 by drying the fibre previous to treating it with oil. When paraffin machinery 

 oil was used, the result was distinctly disadvantageous when dried fibres were 

 employed. It should be added that the fibres which had been oiled after 

 drying re-absorbed a large proportion of their original percentage of moisture 

 on subsequent exposure to the air. 



Colouration of Phormium Fibre. 

 Mr, Skey records some experiments of his own tipon the presence in 

 Phormium fibres of a substance " susceptible of some striking colourific 

 changes." (See Appendix to Commissioners' 1871 Report, p. 92).* The 

 observation is not new, full details concerning this staining of the fibre by the 

 successive application of chlorine and ammonia having been published by 

 M. Vincent in the Comptes Rendus of the Paris Academy a quarter of a century 

 ago. {Comptes Rendus, xxvi., p. 598, 1848.) M. Vincent, indeed, recom- 

 mended the following plan for detecting Phormium fibre : — Soak the fibre in 

 chlorine water for two or three hours ; then wash it with ammonia water ; a 

 violet or pink colour will be developed. But when M. Payen, in 1849 

 {Comptes Rendus, xxix., p. 491), submitted this plan for distinguishing 

 Phormium, from other fi.bres to further scrutiny, he was unable to regard it as 

 satisfactory if applied to thoroughly bleached and cleaned fibres, though it 

 might serve to distinguish Phormium fibre from crude, unbleached, roping 

 fibres of different origin. M. Payen regarded the principle which gave rise to 

 the colour as not essential to the Phormium fibre, but merely adherent to it. 

 The expei'iments of Mr. W, Skey scarcely sanction such a conclusion, bvit 

 rather point to the intimate union subsisting between this principle and the 

 cellular substance of the fibre. I cannot doubt, from my own experiments on 

 this point, that the " encrusting " matter of the fibre is the true origin of the 

 substance which gives the coloured re-action in question. The following 

 experiments seem conclusive on this point, unless, indeed, they go fui-ther, and 

 prove that the pure cellulose of the fibre is itself capable of such a transfor- 

 mation — a position which it would be difficult to accept. 



1st. Experiment on the Pink Colouration of Phormium Fibre after 



Purification. 



One gram of fine native white Phorviium fibre (No. 1 of old reportt 

 was treated with twelve grams of nitric acid of specific gravity TIO, and 0-8 

 gram potassium chlorate, for eighteen days, at a temperature of from 12° 

 centigrade to 18° centigrade. At the conclusion of the experiment, and after 

 suitable purification of the residual cellulose, a proportion of that substance 

 amounting to 83-8 per cent, of the original fibre taken remained. This 



* App. to Journ. H. of R., 1871, G. No. 4. f loc. ciL, G. No. 4a, p. 12. 



