226 



THE ALUMNI JOURNAL- 



similar conditions. Roucher stated {P. L. [3], 

 V » 393) that the reaction was not due to men- 

 thol, and Fliickiger and Power (' Year-Book ' 

 1880, p. 469) suggested that the color might be 

 due to substances combining with alkaline bisul- 

 phites. More recently Polenske has investi- 

 gated the matter, coming to the conclusion that 

 the reaction is probably due to phyllocyanin. 



It was shown in the paper on black and white 

 peppermint oils already referred to that after 

 the removal of the ester." from white oil the 

 color reactions with acid were much less intense, 

 and experiment also shows that the view of 

 Fliickiger and Power, that it is dependent upon 

 aldehydic bodies, is incorrect, as oils give nearly 

 as intense color reaction after treatment with 

 acid sulphite of sodium as before. Moreover, 

 after reduction with zinc dust, intense color re- 

 actions can still be obtained with acids. In 

 order to determine whether the condition of the 

 herbs for distillation rather than the different 

 varieties causes the differences in these reac- 

 tions, I have distilled a small quantity of fresh 

 Japanese peppermint {Mentha atvensis var. 

 piperascens) grown at Sevenoaks, and kindly 

 given me by Mr. Holmes, and the behavior of 

 this oil with nitric acid in glacial acetic acid 

 solution is precisely the same as in the oils dis- 

 tilled from the same species grown in Japan 

 and America, the palest violet coloration being 

 produced. It seems unquestionable, therefore, 

 that this very slight color reaction may be con- 

 sidered as typical of oils of Japanese pepper- 

 mint {M. arvensisvas . piperascens). It is also 

 curious that if the reaction be due phyllocyamin , 

 that this body should be obtained in larger 

 quantity from both varieties of Mentha piperita 

 than M. arvensis var. piperascens. It should 

 be noted also in this connection that, by re- 

 peated distillation of the oil under reduced 

 pressure, the intensity of these reactions is not 

 diminished. 



From the results above recorded it seems pos- 

 sible that the oil produced in America from Mit- 

 cham black peppermint plants is slightly modi- 

 fied, and in certain districts the ester percentage 

 materially increased. The higher ester value 

 of French than English lavender oils has been 

 discussed in my paper on essential oils {Ph. J. 

 [3], XXV., 980), and the opinion expressed that 

 ester determination may be taken as a basis of 

 comparison of oils of the same type. The soft- 

 ness of the French lavender oil compares with 

 the pungency of English oil much as does a 

 higher ester white Mitcham peppermint oil 

 with a black Mitcham oil, or more markedly 



still a Japanese oil. It is unlikely that the 

 higher ester percentage of many Wayne County 

 as compared with Michigan and other American 

 oils is due solely to superior methods of distil- 

 lation. 



It is unfortunate that the American oil so 

 frequently contains spearmint and erigeron 

 oils, as they depreciate considerably the value, 

 even though the menthol ester percentages are 

 high. The difference in climate and soil ap- 

 pears to effect but little alteration in the oil 

 distilled from plants grown in England and 

 America from Japanese roots, the total menthol 

 percentage being only slightly reduced. I am 

 indebted to Mr. Hartford, of New York, for 

 samples of various American oils and plants, 

 and also to Mr. T. Christy, for peppermint 

 plants of the riifferent varieties. 



LIQUOR AURI ET ARSENII BROMATUS.* 



By R. WRIGHT, F. C. S.Ph. C. 



In this note attention was drawn to the uncer- 

 tainty attending the dispensing of the above 

 preparation owing to existing formulae yielding 

 products diflfering materially both in strength 

 and composition and to the desirability of substi- 

 tuting a direct method under the authority of 

 some representative body for the indirect meth- 

 ods at present in use. The preparation is 

 usually made with Clemen's solution — the 

 liquor arsenii bromatus of the United States 

 National Formulary as the starting point; and 

 the author of the paper gave an outline of the 

 published processes for this liquid, and showed 

 wherein they diflfer. 



The original formula for Clemen's solution 



was as follows: 



Take of— 



Arsenious acid 80 grains 



Potassium carbonate 80 grains 



Bromine 160 grains 



Distilled water 15'^ ozs. 



For the production of the liquor auri et ar- 

 senii bromidi the process given in Martindale 

 and Westcott's 'Extra Pharmacopoeia' is as 

 follows : 



Take of — 



Clemen's solution 192 minims 



Gold Bromide iJ4 grain 



Distilled water to i fl. ounce. 



The drawbacks to this process are ( i ) the 

 Clemen's solution must be specially prepared, 

 and (2) there is sometimes a diflSculty in ob- 

 taining a perfectly soluble bromide of gold. 



*Read at the meeting of the British Pharmaceutica 

 Conference. 



