1. The following mixture appears to constitute no danger to fullgrown horses not suffering from congestion of the kidneys, nephritis or gastro-enteritis : "120 c.c. (=4 oz.) of oil of turpentine, 4 c.c. ( = 1 drachm) of extract of male fern, 600 c.c. (=1 pint) of raw linseed oil". As stated before young animals and animals in poor condition should receive half of this mixture, or less, and only pure unadulterated and unoxidised oil of turpentine should be used. 2. Experiments conducted at Onderstepoort with oil of turpentine and extract of male fern are described. 3. The toxic doses, symptoms of poisoning, post-mortem appearances, and treatment of cases of oil of turpentine poisoning are discussed.