208 JOUKNAL OF THE DEPARTMENT OE AGRICULTURE. SePT., 1922. 



Vigilance Committees. — That the Department, in its efforts to 

 eradicate scab, is largely dependent on the assistance of the farming 

 community is being more and more realized, and from many sides 

 offers of assistance are being received. At the Congress of the Cape 

 Province Agricultural Union held last year at Kimberley, the manner 

 in which practical co-operation could be effected was fully discussed, 

 one of the resultant decisions being to found vigilance committees from 

 among the members of local Farmers' Associations. The main object 

 of these committees is to assist the Department in cleaning the district. 

 Although the members of such a committee have no special powers, 

 they can, on account of their local knowledge, assist in many ways, 

 for instance, by bringing to the notice of the local inspector any out- 

 break of scab which has not been reported and any illegal movements 

 which may come to their knowledge. If their district is not already 

 protected, they could encourage the farmers whose flocks are infected 

 to make a special effort to cleanse and keep them clean so that, in 

 course of time, the district could also apply for protection and the 

 consequent advantages. 



Vigilance committees have accordingly been formed in several 

 districts and have proved a great success. It is trusted that this 

 movement will spread over the whole Union and lead to ultimate 

 success in stamping out the disease. 



CHEMISTRY. 



Alleged Toxic Effect of Chemical Fertilizers upon Stock. — Dr. 



Juritz, Chief. Division of Chemistry, writes : In ray note on basic slag 

 in the July issue of the Journal, reference was made to a paper on 

 " Basic Slag and Rock Phosphate " by the New Zealand Agricultural 

 Chemist, Mr. B. C. Aston, F.I.C., which appeared in the New Zealand 

 Journal of AgricnJture of 21st November, 1921, in the course of which 

 he makes the following remark in connection with the use of slag as 

 a top-dressing : — 



" With regard to the poisonous nature of basic slag, the 

 necessity of allowing ample time for the rain to wash the slag off 

 the herbage before depasturing stock on it is one which in most 

 cases can be avoided ; the fact that such poisonings may occur is 

 evidentlv not universally known, and therefore must be pointed 

 out." 



As far as I am aware, cases of poisoning by basic slag are unknown 

 in South Africa; in fact, where it has been spread on pasture-land, 

 although the operation has generally been carried on during a fall of 

 rain, or with rain impending, it has never been the practice to take 

 precautions to keep sheep or cattle from the land during operations. 



Under the circumstances I wrote to Mr. Aston for information as 

 to any local experience he might have in this connection, but he could 

 recall only one such occurrence in New Zealand, namely, in the arid 

 district of Central Ot.ago, where mortality amongst stock was suspected 

 of having been caused by slag. 



The toxic qualities attributed to chemical fertilizers are by no 

 means certain, and the little information available on the subject is 



