554 The Philippine Journal of Science 1923 



figures with the specific rotatory power figures given in Table 

 1, the latter are to be multiplied by the specific gravity. 



Optical rotation is unquestionably the most characteristic 

 simple property of the chaulmoogra group. Many other oils 

 show some rotation, but none outside of the chaulmoogra group 

 are known with a rotation as high as 45° to 50°. Of the oils 

 studied Gynocardia odorata, with no rotation, is definitely out- 

 side of the chaulmoogric group, but Pangium edule shows a 

 rotation of 2.8° to 16.9°. The composition of this oil is dis- 

 cussed on another page. The other oils, definitely in the chaul- 

 moogra group, have the rather narrow range of 43.5° to 51.6°. 

 Taraktogenos kurzii, counting only the authenticated samples, 

 has a range of 43.5° to 46.3°. Our samples of Hydnocarpus 

 anthelminthica, H. hutchinsonii, H. venenata, and H. woodii 

 also fall within these limits, but H. alcalae, H. subfalcata, and 

 H. wightiana give definitely higher values. The inference is 

 that the last-mentioned three oils contain more chaulmoogric, 

 hydnocarpic, or similar acids than true chaulmoogra and are, 

 therefore, slightly superior to it for medicinal use. In our pres- 

 ent state of knowledge, both chemical and clinical, these cannot 

 be considered as established facts, but only as suggestive indica- 

 tions. 



The difference in rotation between the two samples of Hydno- 

 carpus subfalcata is possibly due to the fact that sample A is 

 extracted, while sample B is pressed. 



Iodine number.— The Hanus method was used, one hour being 

 found a convenient time to insure complete absorption. The 

 figure given in each case is the average of two closely agreeing 

 determinations. 



The iodine number is of some value in distinguishing between 

 the different oils of the chaulmoogra group, as may be seen in 

 Table 3. The authentic chaulmoogra samples show an iodine 

 number very close to 100, and Hydnocarpus wightiana is the 

 only other in the chaulmoogra group as high as this. Hydno- 

 carpus alcalae is not much different, but the rest seem to be 

 definitely lower. 



A high iodine number indicates the absence of saturated 

 fatty acids and the presence of acids less saturated than those 

 in the chaulmoogric series; the former are probably relatively 

 inactive, but it remains for clinicians to discover whether the 

 latter are beneficial or harmful. If, as is indicated by Power's 



