— 82 — 



As but little is known of English oil of rosemary, owing to the 

 fact that this oil is not an article of commerce, it was a matter of 

 interest to us to receive recently from Mr. Sawer, of Brighton, an 

 English oil distilled by himself. It had a pleasant, powerful aroma, 

 and showed the following constants: d 15 o 0,9042; a D — 2 49'; a D of 

 the first io°/ — 6° 10'; ester number 9,7; soluble in about 5 and 

 more vol. 80 per cent, alcohol, with very slight turbidity 1 ). 



English rosemary oil differs from the French and Dalmatian 

 by its laevorotation , an observation which agrees with those made 

 previously 2 ). In the case of the two last-named oils, the dextro- 

 rotation is exactly considered a special criterion of purity, and dextro- 

 rotation of the 1 o °/ first passing over on fractional distillation is also 

 required. As we have lately observed a laevorotation in the last- 

 named case, even in oils from a reliable source (though only in very 

 few cases), it may be asked whether this requirement can be upheld 

 without qualification, or whether a slight laevorotation of the first io°/ 

 of the distillate may be permitted if the specific gravity is suf- 

 ficiently high? 



For the present, we must still insist on our former requirements, 

 and we reserve a definite opinion on this question, until we have 

 had before us a more voluminous authentic material for ob- 

 servation. 



Some years ago we published a note on Spanish oil of rose- 

 mary 3 ), according to which this oil differs from the French and 

 Dalmatian by its higher specific gravity and its more powerful rotation; 

 the ester-content was also higher, as saponification numbers were found 

 up to 37, whilst otherwise they hardly exceed 12. But as we also 

 repeatedly received Spanish oils which were in every respect the same 

 as the French and Dalmatian distillates, we believed that the above- 

 mentioned differences were due to the fact that in those cases the 

 rosemary distillate was not pure. This surmise has now been con- 

 firmed. According to information received by us from Spain, there 

 exists in that country, besides the ordinary rosemary oil, which is 

 quite normal in its behaviour, also an oil designated an "rosemary 

 oil c our ant" which is distilled from rosemary and sage, and which 

 differs in the manner described above from ordinary rosemary oil. 

 An oil of this kind recently examined by us had the following con- 

 stants: d 15 o 0,9258; «d-[-I4 35 / ; a D of the first 10 °/ ~-{- o° 40'; 



1 ) The oil had been distilled from herb gathered in the autumn (22. Sep. to 

 30. Oct.). A distillate from the same source, made from hibernated herb cut in 

 April, had approximately the same constants as the one described above: di 5 o 0,9047; 

 a D — 2° 28'; ester number 6,52 ; soluble in about 5 and more vol. 80 per cent, alcohol. 



2 ) Sawer, Odorographia, Vol. I, 370. 



3 ) Report April 1900, 37. 



