AbstractAn account is given of the difficulties encountered in applying an existing standard method of analysis of coal tar preparations to the separation of the constituents of certain fungicides used for treatment of rubber‐tree disease. The method which was developed to overcome these difficulties is described. The scheme of analysis involves the preliminary removal of water and formulating materials, using simple apparatus, and is followed by countercurrent extractions. Recovery of the separated groups of constituents appears to be good and will enable an assessment to be made of their contribution to the biological activity of the original material