MIXT. 213 



result from oil and climate. On account of this I took greater 

 pains to verify my determinations by testing samples grown under 

 much varying conditions of soil and climate, both in Europe and 

 America. Forty-three samples were examined, including oils 

 produced in St. Joseph, Wayne, Ionia, Hillside and Kalkaska 

 Counties, Michigan, Wayne County, Xew York and vicinity (all of 

 which were produced from American roots long acclimatised) ; also 

 one specimen grown in America from roots imported from 

 England, and one specimen grown and distilled in England. The 

 sp. gr. has been variously stated in Dispensatories and other 

 standard works at from 0*840 to 0-950 at 60^ F. But there were 

 none of the samples which were pure which had a sp. gr. below 

 0'910 at 60^ F., except the two last mentioned, grown from 

 English roots ; the one grown in America being 0-9085, the one 

 distilled in England being 0-9088. Xor were any specimens of 

 pure oil found having the sp. gr. above 0-917 which were in a 

 perfectly soluble condition. One sample distilled by myself in 

 1875, and consequently eleven years old, had, on account of its 

 age, a sp. gr. of 0*924 ; one sample from Xew York 0-933, and 

 another from the same district 0-940. However, these three 

 samples were found to be not readily soluble ; the latter sample, 

 when submitted to rectification, being found to contain 9 per cent, 

 of insoluble resin. Of five samples imported from Europe, but one 

 was found pure; two from Germany were found to contain 

 dementholized oil of Mentha arvensis ; one from London, which 

 bore a fraudulent and forged label (as Michigan oil of peppermint, 

 manufactured at Evart, Michigan County, U.S.), had the sp. gr. 

 0-899. This oil, when submitted to fractional distillation, was 

 found to contain 50 per cent, oil of turpentine, and no Michigan 

 peppermint whatever. The sample imported from London as 

 " German oil of peppermint " consisted chiefly of Pennyroyal and 

 Mentha arvensis. Allowing a slightly wider range of difference than 

 was really intended, it is evident that whether from English or 

 American plants, pure oil of peppermint is never below 0-908 sp. 

 gr., nor, when fresh and soluble, above 0-917 sp. gr., so that the 

 difference formerly allowable, that is, from O'SIO to 0-950, is 

 reduced to one-tenth." 



Kespecting the tests for purity of (English and American) oil of 

 peppermint, Mr. Todd, in the paper above referred to, states : — 

 " Oil of peppermint, when freshly distilled, or when two or three 



