§ 46. DIRECT EXTRACTION WITH ETHER. 37 



and the substances thus dissolved estimated. Iq the majority o£ 

 cases the weight will be the same as the sum of the substances 

 extracted by petroleum spirit according to § 9, and ether according 

 to § 36. If there is a deficiency, the residue should be treated 

 vrith petroleum spirit, in which case attention would be directed 

 to a substance other than an ethereal or fixed oil. The residue 

 after exhaustion with ether, and, if necessary, petroleum spirit, 

 may be dried and boiled with chloroform or bisulphide of carbon, 

 to ascertain if such substances as ccmUtJiouc, eta can be extracted 

 (§ 127). 



