265 
1918 .] The N.Z. Journal of Science and Technology. 
dyestuff alizarin was first prepared. New Zealand is the headquarters of 
the genus Coprosma, containing some sixty species, about two-thirds of 
which are endemic to New Zealand, where they everywhere form a large 
proportion of the shrubby vegetation, whether in littoral scrub, lowland 
forest, or subalpine scrub. 
Of the thirty-nine species of Coprosma described by Cheeseman in the 
Manual of the New Zealand Flora (1906), nineteen occur in the vicinity of 
the City of Wellington. These are Coprosma grandifolia Hook, f., C. lucida 
Forst., C. Baueri EndL, C. robusta Raoul, C. Cunninghamii Hook, f., 
C. rotundifolia A. Cunn., C. areolata Cheesem., C. tenuicaulis Hook, f., 
C. rhamnoides A. Cunn., C. parviflora Hook, f., C . Buchanani T. Kirk, 
C. crassifolia Col., C. acerosa A. Cunn., C . propinqua A. Cunn., C. Kirkii 
Cheesem., C. linariifolia Hook, f., C. foetidissima Forst., C. Colensoi Hook, f., 
C. microcarpa Hook. f. Of these only some half-dozen of the more abundant 
have been tested for dyeing-capacity. These are C. grandifolia, C. lucida, 
C. Baueri, C. robusta, C. areolata, and C. foetidissima. Owing to the small 
size or rarity of the other species it was not thought desirable to include 
them within the scope of the present experiments beyond examining the 
colour reactions which they yield on treatment with alkalis. Some of 
these last would no doubt yield interesting results, notably C. linarii¬ 
folia (the mikimiki, or yellow-wood), which, although rare in Wellington, 
is commoner in the South Island, where it attains a good size and is 
remarkable for the yellow colour of the wood. Of the six larger and 
commoner species mentioned, C. grandifolia and C. areolata certainly fall 
into a class apart in giving purplish or maroon fast dyes on chrome 
mordants with wool, and orange-scarlet (tangarene) to dark-red shades 
with stannous mordants and tartar in the single-bath method. C. grandi¬ 
folia has a yellow bark,* the depth of colour varying in different trees. 
From this species the dye is best extracted from the bark by comminuting 
it in a mincing-machine, digesting in water with gentle heat, and washing 
three times with warm water, which is strained off by means of a filter 
frame covered with cheesecloth, the wash water being discarded, finally 
extracting the pulp with very dilute caustic-soda solution (0*05 per cent. 
NaOH) with the aid of gentle heat. Three extractions are usually sufficient, 
and a pound of bark will dye a pound of wool. The solution generally 
becomes acid on standing, but if alkaline should always be made acid with 
acetic acid before using in the dye-bath. Attempts to use the wash water 
instead of the alkaline extract as a dye-beck, although resulting in darker 
colours with alumina mordants, have not proved satisfactory. The wood 
of Coprosma grandifolia is often yellow, especially the root wood of the 
older trees in winter, and yields, by a method similar to that employed 
with the bark, a light-brown fast dye on chrome mordants. Five pounds 
of finely divided yellow wood will dye a pound of wool a good light brown, 
but with larger quantities of wood very dark reddish-browns are obtained. 
The wood in the dry state retains its dyeing-power for several months, as 
recent experiments with wood gathered in November last proved. The 
wood is best reduced by passing fresh chips reduced by a chopper through 
an Enterprise fowl-grit machine, from which it is discharged as a coarse 
sawdust. 
* The term “ bark ” is used in this paper in a general sense to denote the cortical 
and adjoining tissue which is easily removable in sheets from the tree, and the colour 
and colour reactions refer to the inner surface of such sheet. 
