NoTEls. 703 



5. Individual trees of the same size, and from the same planta- 

 tion even, differ considerably in the thickness of their bark from 

 corresponding sections, showing that this factor depends very largely 

 on the conditions under which the tree has been growing. 



6. The thickness of tlie bark is a fairly safe criterion of its rich- 

 ness in tanning' matter, no matter what the age of tlie tree is, provided 

 no " cnrkiness " has developed in the bark. 



7. The colour of i]\v infusion from tlie bark (hM'])eus sliglitly witli 

 tlie age of the tree. 



8. In the case of mature wattle bark that lias been carefully 

 harvested and dried in the open air, the depth of the red colour in 

 the infusion of standard strength obtained from it varies from 3 up 

 to 5 units, and the yellow colour usually varies from 3.5 to 7 units. 

 This compares favourably with most natural tanning materials. 



9. When a weak extract from wattle bark is cooled and allowed 

 to stand, a large proportion of the difhcultly soluble bodies are soon 

 precipitated, with a corresponding loss of soluble non-tanning matter, 

 while the proportion of tanning matter slightly and gradually 

 increases. 



10. When a weak extract is boiled for a moderate length of time, 

 there is only a slight loss of tanning matter with a corresponding 

 increase in the proportion of soluble non-tanning matter. There is, 

 however, a marked deterioration with regard to the colour of the 

 infusion. 



11. In the commercial samples of solid wattle extracts manu- 

 factured in Natal, the proportion of tanning matter usually varies 

 from 59 up to 67 per cent. 



Exhibition of Cinema Films depicting South African 

 Agriculture. 



In connectiini with the Governmenf^s scheme for advertising the 

 Union and its resources, the Department of Mines and Industries, in 

 collaboration with this Department, is preparing a number of films 

 depicting farming scenes and operations in South Africa. The films, 

 which are to be shown first throughout the Union and subsequently 

 in a number of oversea countries, will illustrate the following : 

 Tobacco growing and manufacturing, fruit growing, fruit drying and 

 exporting, wine and brandy, dairying, cotton, forestry, ranching, 

 maize, land settlement in the Union, development of irrigation and 

 the Avater-power resources of the Union, wool, mohair, the Govern- 

 ment'-s share in promoting scientific agriculture (including 

 work at the schools of agriculture, experiment stations, and labora- 

 tories), transport and communications, etc. 



This is an age of advertising, and the Union is falling into line 

 with other countries in making known our many resources. High 

 hopes are entertained that, as a result of the publicity campaign and 

 the attraction of capital and other advantages which are expected to 

 ensue, material benefit will accrue to the agricultural life of the 

 Union. 



