﻿AN ECONOMIC STUDY OF ACACIAS. 21 



grass covered and therefore required no clearing. Rows were marked 

 at 12 feet apart and the seed was hilled 6 feet apart in the rows. 

 Corn was grown between the rows for the first two years in order that 

 its yield would help to reduce expenses. At 10 years old the trees 

 were 10 inches in diameter. 



All the work on this 2,400 acres is clone by 60 natives, who peel, 

 cut, and dry the bark, stripping it at any season that it will peel 

 easily. They use drying sheds of galvanized iron, each one of which 

 holds about 6 tons of bark. 



The gross receipts from 10-year-old trees at the price of $32 per ton, 

 when Mr. Fairchild made the study, was from $161 to $193 -an acre. 

 The operating cost for harvesting the product was $7.30 a ton or 

 $43 an acre. The 10 years' care of the land, the cost of the land — 

 in this case only from $5 to $6 an acre — and interest were said to be 

 covered by the sale of the wood for mine props, fuel, and small timber. 

 No replanting has been necessary, since thousands of seedlings come 

 up and cover the ground. 



Another valuable publication on acacias in Natal has been fur- 

 nished by Mr. T. R. Sims; 1 but the most complete publication which 

 covers the entire industry in 10 countries is the third edition of 

 Dr. Maiden's "Wattles and Wattle Barks." 



NORTH AFRICA. 



Johannes Paessler, of Levertechn, published in 1910 a paper on 

 acacia bark grown hi North Africa, in which he speaks of Acacia 

 decurrens, decurrens mollis, decurrens dealbata, pycnantJia,' and pen- 

 ninervis. According to his report only the best species are planted 

 and the tannin yield, which was less than 30 per cent, is now increas- 

 ing. Acacia decurrens hi German East Africa, at an elevation of from 

 4,000 to 4,500 feet is ready for gathering at five years, and yields a 

 bark of higher tannin content than that from Natal. At Freiburg 

 Station 260 bark samples were analyzed by the filter method since 

 1901, with the folio whig averages: 



Per cent. 



Tannins 33 



Nontannins 8. 5 



Insolubles 43 



Water 14. 5 



There is a smaller proportion of nontannins to tannins in acacias 

 than in the domestic barks, such as oaks. The sugar content is very 

 low, which gives the acacias only slight acid-forming power. Ground 

 acacia bark, according to this report, hi Germany in 1910 cost $55 

 a ton, which makes the tan worth about 8^ cents a pound. 



1 "Tree Planting in Natal," Chapter 9: "The Black Wattle Industry," Bulletin 7 of the Natal Depart- 

 ment of Agriculture, Pietermaritzburg, 1905. 



