— 134 — 



content 5 to 15%, free menthol content 45 to 6o°/ . Schimmel & Co.: 

 di 5 o 0,900 to 0,910; «d — 23 to — 30 ; total menthol 50 to 66°/ . 

 With 4 to 5 vols. spir. dil. peppermint oil should give a clear, or at 

 most a slightly opalescent solution. 



We expressly abstain from insisting upon an absolutely clear solu- 

 tion in dilute spirits, because even in the case of good English oils 

 slight opalescence is occasionally noticeable. 



As regards the menthol content it appears to us, in the case under 

 discussion, to be more practical simply to state the total menthol per- 

 centage, i. e. the value resulting from saponification after acetylation. 

 In doing so, it is true that no account is taken of the fact that part 

 of the menthol occurs in the oil as an ester, but the values obtained 

 are at most 2 or 3 °/ too high and will therefore be amply sufficient 

 in practice. Separation into esterified menthol and free menthol would 

 complicate the test needlessly. 



v. Soden justly points to the difficulties which exist in estimating 

 the quality of peppermint oil. He recommends either to lay down 

 general constants and to admit all varieties of peppermint oil, or 

 to incorporate only two kinds of peppermint oil, namely English oil 

 on the one hand and all other kinds on the other. We only regard 

 the first suggestion as acceptable, the other would doubtless be found 

 to have many drawbacks. At the time we suggested to the Authorities 

 concerned the advisability of admitting oil from Mentha piperita and 

 from varieties of Mentha closely allied thereto in order to avoid as far 

 as possible the difficulties that would otherwise crop up. Of course, 

 if this were done it would be necessary so to fix the constants that 

 the pharmacist would have a guarantee of receiving good oil. 



Rose Oil. v. Soden: d 3 oo 0,849 to 0,862; a v — l0 3 ' t0 — 3°; 

 Schimmel & Co.: dsoo 0,849 to 0^63; « D — 1 to — 3 . 



Sandalwood Oil. v. Soden: di 5 o 0,975 to 0,980; «p — i6°30 / 

 to — 20 ; Schimmel & Co.: di 5 o 0,975 to 0,985; «d — 16 to — 20 . 



v. Soden proposes to fix the minimum content of santalol at 92 °/ , 

 calculated for C 15 H 24 0. We should not like to endorse such a pro- 

 posal, for according to our experience with our own distillates even 

 oils made from the best materials occasionally contain a little less 

 santalol that this. The commercial practice of requiring a minimum 

 of 9O°/ is in our view the one most in harmony with facts. 



v. Soden's recommendation to discard sandalwood oil in favour 

 of santalol, we should certainly not be able to endorse, principally 

 because of the increase in price which would thereby be made un- 

 avoidable for a medicament which is already rather expensive. 



