The estimated expenditure on a wattle-bark plantation of 100 acres during 8 years is:—
| £ | s. | d. | |
| Rent of 100 acres for 8 years at 6s. per acre per annum | 240 | 0 | 0 |
| Ploughing 100 acres in drills 10 ft. apart | 25 | 0 | 0 |
| Sowing wattles and actual cultivation, including cost of seed | 37 | 10 | 0 |
| Supervision for 8 years (nominal), say 10l. per annum | 80 | 0 | 0 |
| Pruning the trees, taking off useless wood (necessary for 2 years), 10s. per annum | 50 | 0 | 0 |
| Incidental and unforeseen expenses | 27 | 10 | 0 |
| Interest on the whole amount expended during 8 years | 240 | 0 | 0 |
| 700 | 0 | 0 | |
| Actual cost of stripping and carting, as shown below | 1515 | 0 | 0 |
| £2215 | 0 | 0 |
The receipts derivable from a wattle plantation of 100 acres, planted in the manner proposed, would be:—
| £ | s. | d. | |
| Each acre planted with wattles, 10 ft. apart, would carry 400 trees, and at end of 5th year trees would yield say 56 lb. matured bark: stripping only every 3rd tree, 332 trees would be obtained off 100 acres: this, at 4l. per ton, would give for 1st stripping | 1332 | 0 | 0 |
| In the 6th or following year, a similar number of trees would be stripped: the bark having increased in weight (say 14 lb.), the increased yield of 2nd stripping would be 400 tons at 4l. per ton | 1600 | 0 | 0 |
| In the 7th year, the remaining trees would be stripped, from which a still greater increase would be obtained, say 480 tons at 4l. per ton | 1920 | 0 | 0 |
| Total yield of bark | 4852 | 0 | 0 |
| The cost of stripping would not exceed 15s. per ton, on account of the facilities presented by the regularity of the trees, while carting would represent another 10s. per ton: these combined charges would be 25s. per ton, and on 1215 tons, would be | 1515 | 0 | 0 |
| Leaving a clear profit on the 100 acres of | £2637 | 0 | 0 |
The exports of mimosa-bark in 1876 were 11,899 tons from Victoria, 4758 from South Australia, and 1735 from Tasmania. Later returns are included in barks, [p. 39]. Shanghai imported 7038 piculs (of 1331/3 lb.) in 1879. The approximate London market values of mimosa-bark are:—Ground, 6-13l. a ton; chopped, 5-12l.; long, 5l.-9l. 10s. A very superior extract has been made from this bark.
Myrobalans or Myrabolams.—The fruits of several species of Terminalia constitute the myrobalans of commerce; they are chiefly T. Chebula and T. Bellerica, natives of India, the former being a tree 40-50 ft. high, and esteemed for its timber also. The fruits contain 30-35 per cent. of gallotannic and ellagitannic acids, producing a soft and porous tannage, and good samples giving a bright-yellow colour. The tannin exists in the pulp, and is absent from the very hard "stone." The dried fruits are known locally as har, harra, or bahera, and are used commonly for dyeing, but not for tanning.
Our imports of myrobalans in 1880 were:—238,151 cwt., 121,465l., from Bombay and Sind; 115,670 cwt., 51,339l., from Madras; 11,020 cwt., 4717l., from Bengal and Burma; 3520 cwt., 1402l., from other countries; total, 368,361 cwt., 178,923l. Our re-exports in 1880 were 8015 cwt., 4328l., to Germany; 16,127 cwt., 8515l., to other countries; total, 24,142 cwt., 12,843l. The approximate London market values of myrobalans are 7-14s. a cwt. for good, and 5-10s. for common. Shanghai imported 4403 piculs (of 1331/3 lb.) in 1879.
Oak-barks (Fr., Écorces de Chêne; Ger., Eichenrinden).—The barks of several species of oak have valuable tanning properties. They are chiefly:—The common oak (Quercus Robur, varieties: sessiliflora, Ger. Traubeneiche; pedunculata, Ger. Stieleiche), which is of even greater importance as a timber-tree; the cork-oak (Q. Suber); the evergreen oak (Q. Ilex); and the American chestnut-oak (Q. Castanea). These barks are among the most esteemed tannins as regards quality of leather, but are incapable of giving much weight, and from their bulk are costly to handle, containing only 10-12 per cent. of tannin (quercitannic acid). They give a reddish fawn-coloured leather, and deposit a good deal of bloom, but yield little or no gallic acid. The barks of the cork-oak and evergreen oak from Southern Europe, are stronger and darker-coloured than English bark. The American chestnut-oak contains a peculiar fluorescent principle like æsculin.
Our imports of unspecified barks for tanners' and dyers' use in 1880 were:—189,399 cwt., 101,108l., from Australia; 123,302 cwt., 32,974l., Belgium; 57,232 cwt., 20,988l., United States; 22,100 cwt., 6030l., Holland; 18,648 cwt., 3676l., Italy; 16,151 cwt., 6972l., Algeria; 22,669 cwt., 8838l., other countries; total, 449,501 cwt., 180,586l. Our imports of unenumerated bark-extracts in the same year were valued at:—516,578l. from Holland, 92,654l. France, 30,187l. United States, 16,315l. British North America, 12,796l. Belgium, 13,769l. other countries; total, 682,299l. Our re-exports of barks in 1880 were:—19,548 cwt., 10,348l., to Germany; 14,627 cwt., 7425l., France; 4555 cwt., 3041l., Holland; 10,304 cwt., 6080l., other countries; total, 49,034 cwt., 26,894l.