Which method is specifically cited as a variation of the dry gum method for emulsions containing volatile oils?

• A. Oil method
• B. English method
• C. Emulsifier in oil method
• D. Forbes bottle method

Answer: (D)

The key idea is preserving volatile oils during emulsification. In the dry gum method, you combine gum with the oil phase and then add water gradually to form the emulsion. The Forbes bottle method adapts this approach by doing the emulsification in a tightly sealed bottle and shaking vigorously, which minimizes loss of volatile components through evaporation. This containment is essential when volatile oils are present, making the Forbes bottle method the specific variation suited for those emulsions. Other methods either modify the mixing sequence or rely on different equipment, but they don’t address the evaporation risk as explicitly as the Forbes bottle method does.