262 Transactions. — Chemistry. 



on the exterior of the leaf much of the difficulty expei'ienced in bringing 



various chemicals to act iipon the cellular substance of the leaf itself is due ; 



it also retards the commencement of the retting and fermentation processes 



for the preparation of the fibre. Of course, the removal of this greasy bloom 



could not be economically efiected on a manufacturing scale by means of a 



solvent like ether, or even by the use of that much cheaper and still more 



powerful agent, the bisulphide of carbon (CSg) ; but it might be woi-th while 



to see how far a brief immersion of the leaf in an alkaline or soapy liquor 



would answer in actual practice. As an alkaline lye might be prepared from 



the ashes of the rejected parts of the leaves, the cost of such a treatment as 



that just suggested need not be considerable. Laboratory experiments have 



shown me that leaves cleansed from the surface-wax by means of a boiling 



alkaline solution, are far more easily acted upon by the materials used in their 



subsequent treatment. It may be here remarked that in the treatment of the 



dried plant with boiling alcohol, a sohition of many of the proximate principles 



of the plant is obtained, and amongst these some of the wax or fat will be 



found; but, as the solution cools, the greater part of this substance is 



deposited in granules, which are soluble in ether, and which fuse below the 



heat of boiling water. 



C. — Sugar. 



In determining the existence and proportion of sugar in the Phormium 

 leaf, two plans were adopted. When an alcoholic extract of the leaves had 

 been prepared, as described further on, under the heading " Bitter Principle," 

 it yielded, after treatment with lead subacetate and separation of the resulting 

 precipitate, a solution which contained certain lead compounds along with the 

 bitter principle, and much siigar. This solution was freed from lead by means 

 of sulphuretted hydrogen (H2S), and then, after filtration and concentration, 

 gradually deposited a considerable amount of amorphous sugar. This sugar 

 corresponded closely in properties to the sugar of acid fruits, known a^ fructose 

 or Icevulose. It was soluble in alcohol, and reduced the red oxide of copper 

 from Pehling's sugar test very readily. A rough determination of its amount 

 gave 4*3 per cent, as existing in the fresh leaves. This number is much 

 higher than the estimate recorded by Dr. Hector in 1865 (1 to 1"5 per cent.) ; 

 but I consider it rather under than beyond the truth. This apparent 

 discrepancy may, however, be capable of ready explanation. The leaves of 

 Phormium upon which my experiments were necessarily made, had been 

 grown in a greenhouse at Kew. The plant was a good deal shaded by the 

 crowding of other foliage, and altogether was growing under quite artificial 

 conditions. These conditions may have been, and are likely to have been, 

 peculiarly favourable to the production of sugar. 



When an aqueous extract of the plant was prepared, a still higher pei'- 



