H.—34,

10

results are selected from a largo number which were obtained, but which I do not think would be of any service if introduced into this Eeport:— A. Native— good. B. Machine—good. C. Machine—ordinary. Percentage of oil (colza) retained 7 ior> t? n i a r- __•_!»_.._ f loo 17 0 14*6 by moist fiores ... ... ) Percentage of oil (colza) re- ) ,00 i.>.q ip.q tamed by dried fibres at 100° c. ) Oiling Experiments, Series IV. An animal oil (sperm oil), having the sp. gr. "927, was used for these experiments, which were ia other respects conducted as before. As in Series 111., the previous drying of the fibres made but little diiference in the amount of oil retained after pressure and hammering. However, the character of the treated fibres showed a distinct superiority over those dressed with vegetable oil. A few of the results are here given : — A. Native —good. B. Machine—good. C. Machine—ordinary. Percentage of oil (sperm) re- ") , 0 . 0 ,_.. .„ . _ ■ jil • __v c l/o lo 4 lo 4 tamed by moist fibres ... J Percentage of oil (sperm) re- \ -..-..Q , r ,„ ... tamed by fibres dried at 100° c. j It will be seen that in all the series no appreciable advantage was gained by drying the fibre previous to treating it with oil. AVhen paraffine 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 reabsorbed 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 upon the presence in Phormium fibres of a substance " susceptible of some striking colourific changes." (See Appendix to Commissioners'lB7l lleport,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, recommended 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. Pay en, in 1849 {Comptes Rendus, xxix., p. 491), submitted this plan for distinguishing Phormium from other fibres 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 experiments of Mr. W. Skey scarcely sanction such a conclusion, but 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 further, and prove that the pure cellulose of the fibre is itself capable of such a transformation —a position which it would be difficult to accept. Ist. Experiment on the Pink Colouration of Phormium Fibre after Purification. One gram of fine Native white Phormium fibre (Xo. 1 of old Eeportf) was treated with twelve grams of nitric acid of specific gravity l'lO, and oB 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 residu.il cellulose, a proportion of that substance amounting to 88*8 per cent, of the original fibre taken remained. This cellulose did not acquire any colour'by treatment with ammonia, but chlorine water followed by ammonia water did stain it pink. When this fibre, so treated (with nitric acid and potassium chlorate), was further acted on by means of water at a temperature of 150° centigrade for four hours, it gave a yellow* acid liquid, and lost a considerable portion of its weight. And yet, after this second and most severe purification, the residual cellulose still gave the characteristic pink colour after a few minutes' soaking in chlorine water and the subsequent application of ammonia. It is impossible to regard the substance susceptible of the colour-change as other than a transformation-product of the very substance of the fibre itself. 2nd. Experiment on the Pink Colouration, fyc. A similar purified sample of Phormium fibre, but in the preparation of which the acid and alkali method had been employed, gave, a dark red-brown colouration with chlorine water followed by ammonia. Miscellaneous Observations on Phormium Fibre and the Fresh Plant itself. Some experiments on the action of an ammoniacal solution of copper upon the constituents of the fibre were made with the hope of gaining some further insight into the cellulosic constituents of Phormium. The results were not accordant with each other, nor with the deductions from the results of other methods of analysis. It was found that the above-named reagent dissolved out onty 21 per cent, of cellulose from a fair sample of machine-dressed Phormium fibre, but that it extracted no less than 40 per cent, of cellulose from a sample of the same fibre which had been treated with nitric acid and potassium chlorate. Thus it appeared that this latter treatment opened up the fibre to the more complete penetration and solvent action of the ammoniacal copper solution. In another experiment the residue of the action of oil of vitriol upon a sample of Phormium fibre was submitted to the action of the reagent for cellulose. In this case the presence of some cellulose was also indicated, although the previous treatment with sulphuric acid (of sp. gr. 153) should have removed it altogether. * Appendix to Journals, H. of E., 1871, Ot. Ko. 4. + Appendix to Journals, H. of E., 1871, G. No. 4a, p. 12.