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LXI. Hcmarhs on the Compoimds derived from the Stearopteii 

 of Oil of Peppermint. By Robert Kane, M.D.^ M.R.I.A.* 



T N iny paper on the constitution of the essential oils, 1 no- 

 ticed that the composition of the oil of peppermint as 

 determined by my analyses approximated to that announced 

 by Blanchet and Sell as belonging to the solid crystalline 

 substance which often forms in it ; but at the same time I 

 stated, that from the utter discordance of Blanchet's results 

 among themselves, no confidence could be placed in them. 

 The formula I adopted for oil of peppermint is Cq^ HgoOg, 

 and in order to establish a more direct comparison I will 

 subjoin two of the analyses by which that formula was esta- 

 bUshed. 



Experiment. Theory. 



I. II. 



Carbon 78-06 



Hydrogen.. 12-32 



Oxygen ... 9*62 



77-81 



^21 



128-9 



78-U 



12-11 



H20 



20-0 



12-12 



10-08 



0, 



16-0 



9-74 





Theory. 





Cm 



61-40 



77-28 



^m 



1000 



I2-59 







8-00 



10-12 



100-00 100-00 164-9 100-00 



The two analyses of the stearopten made by Sell and 

 Blanchet, gave results which I will also subjoin. 



Experiment. 



I. II. 



Carbon 79-63 77*27 



Hydrogen.. 11-25 12-96 



Oxygen ... 9-12 9*77 



79-40 100-00 

 The total discordance of these results, coupled with the fact, 

 that on analysing the liquid oil of peppermint Blanchet and 

 Sell had obtained numbers quite different from each other, 

 and from the truth, shows that for purposes of further re- 

 search the investigations of Blanchet and Sell cannot be taken 



o 



as a standard. 



Mr. Walter has recently published a memoir on the cry- 

 stallized essence (stearopten) of peppermint, in which he 

 lays down as the basis of his very interesting researches 

 Blanchet's formula, and supposes that its truth is confirmed 

 by his own analyses. With this I should not, however, have 

 anything to do, had not Mr. Walter made the same obser- 

 vation with me, of how close my formula for the liquid oil 

 approached to Blanchet's for the stearopten, and insinuated 



* Communicated by the Author. 



