396 Journal of the Department op Agriculture. 



animals may be immunized. The first method can be resorted to in 

 cases where an insect-proof stable is available and only a compara- 

 tively small number of trained horses have to be handled. Such animals 

 should then be stabled at night. If the stable is not mosquito-proof, 

 it should be smoked out at night, or the animals should be rubbed 

 down with some fly-repellant. Another w^ay of preventing infection 

 is to remove the animals to a high area. Attempts have also been 

 made to dij) horses regularly in a mixture that Avill repel biting 

 insects. This method has met with partial success, but further 

 experiments are necessary. 



At the present time the imniunization of mules and horses is 

 the best preventive measure. The method of preparing an immune 

 serum and the difficulties encountered in the course of preparation 

 are described. The inoculation of mules has been carried out on a 

 fairly extensive scale; more than 30,000 animals have been done since 

 1905, with excellent results. In horses the method is much more 

 complicated. Three different inoculations are necessary. Neverthe- 

 less, the method has been employed on a great number of aiiimals. 

 On the whole the results (at any rate with horses inoculated at the 

 laboratory at Onderstepoort) have been satisfactory. In the country 

 certain difficulties have been encountered. The greatest setback was 

 the outbreak of staggers (malsiekte) in the inoculated horses a few 

 years ago. The cause of this disease has not yet been fully elucidated ; 

 but one of the main factors that seem to bring on this strange condi- 

 tion is work. If the animals are given a sufficiently long rest after 

 the inoculation, the danger of their contracting staggers is very much 

 reduced. 



In this connection attention may again be drawn to the notes 

 about the inoculation against horse-sickness that appeared in the 

 March, 1921, issue of this Journal (p. 207). Attempts are continually 

 being made to improve the method of inoculation, and the results 

 obtained during the last few months at Onderstepoort have been so 

 encouraging that the hope seems justified that in course of time this 

 scourge will be brous'ht under control. 



The Oversea Market for Soutli African Produce. 



The recently issued report* of Mr. Canham, the Union's Trade 

 Commissioner in London, for the year 1919, the first of its kind issued 

 since the 1913 report of Mr. Chiappini, the former Trade Commis- 

 sioner, gives valuable information on that matter 'of supreme 

 importance to the South African producer, the progress made by his 

 products on the oversea market. The report deals in detail with our 

 l)rin('ipal products, and combines well-considered advice with most 

 useful statistics While our interests are Aery largely centred in the 

 Londoji market, and the reporl is concerned principally with condi- 

 tions existing there, Mr. Canham contributes an interesting chapter 

 on the Continental market ; in Holland he gained a decidedly favour- 

 able impression of trade possibilities between that country and the 

 Union, dependent upon the establishment of proper shipping facilities. 

 He refers also to the question of trade with France, Belgium, and 



*" Report of the Acting Trade Commissioner for the year 1919," obtainable from the 

 Government Printer, price 5s. 



