- 6 9 - 



fully picked leaves contains lsevorotatory fractions. Finally it is evident 

 that oil from the leaves only has a higher borneol- content, and 

 consequently also a finer odour. 



On the strength of Parry and Bennett's observations, the "Chemist 

 and Druggist" 1 ) finds fault with the observation 2 ) made by us when 

 discussing the Spanish Pharmacopoeia, that pure rosemary oil is dextro- 

 rotatory, and that Isevorotation points to adulteration with French oil 

 of turpentine. We would reply to this that these statements are based 

 upon the observations made up to the present, according to which 

 the pure lsevorotatory oils in commerce belong to the exceptions. But 

 when the Spanish Pharmacopoeia excludes the dextrorotatory rosemary 

 oils, it is in direct contradiction with the facts. In any case it will 

 be well to continue exercising care in dealing with lsevorotatory rose- 

 mary oils. 



The fact that the time of the year also influences the quality of 

 the oil contained in rosemary, appears to have been proved by 

 A. Birckenstock 8 ). In order to show that rosemary plants from the 

 same ground and soil (St. Bauzille de Montmel, Herault), worked up 

 under exactly the same conditions, yield oils of different rotatory powers, 

 three distillations were carried out, viz., in the spring, summer and 

 autumn. On the other hand, samples of rosemary from Cannes (Alpes 

 Maritimes) were distilled in the spring and summer. The authentically 

 pure oils showed the following optical behaviour: — 







a D of the 



a D of the 



a D of the 







a jy of the 



I st fraction 



2 n( lfraction 



3rd fraction 



Residue 





oil 



io°/. 



i6°/o 



i«°/o 





Herault, spring (April) . 



+ 6° 3 2' 



— 4° 10' 



- 3° 10' 



— I° 4 2' 



+ 13° 6' 



Herault, summer (July) . 



+ 8° 17' 



— o°28' 



+ o° 5 o' 



+ 2° 5 2' 



+ 13-16' 



Herault, autumn (end of Nov.) 



+ 11° 



+ i°5«' 



-f 2° 6' 



+ 3°iS' 



+ i6° 5 7' 



Cannes, spring (13 April) 



- o° 5 7' 



-i3°38' 



-n°35' 



— 



+ i6° 5 7' 



Cannes, summer (end of June) 



+ 5°57' 



- *° 4' 



— i°i6' 



+ o° 3 o' 



+ "° 7' 



In the case of Spanish rosemary oil the case is this, that the 

 rotation has always been found to the right, but has decreased con- 

 siderably in the autumn. Both oils, Spanish and French, show fluc- 

 tuations in the pinene-content, but the former contains d-pinene pre- 

 ponderatingly in the spring, and is in that season richer in pinene 

 than in the autumn, which may be concluded from the low specific 

 gravity (d 150 0,8851) of the spring oil. Birckenstock's examinations 

 therefore allow the conclusion to be drawn that the view, that lsevo- 

 rotatory rosemary oils are adulterated with turpentine oil, does not 



1 ) Chemist and Druggist 69 (1906), 137. 



2 j Report April 1906, 85. 



3 ) Moniteur scientifique Quesneville, May 1906. 



