HEKBA ROSMAIUNI 489 



Description — Rosemary has sessile, lir.car, entire, opposite leaves 

 about an inch in length, revolute at the margin ; they are of coriaceous 

 texture, green and glabrous above, densely tomentose and white beneath. 

 Examined under a lens, the tomentum both of the leaves and young 

 shoots is seen to consist of white stellate hairs ; in that of the shoots 

 which is less dense, minute oil-glands are discernible. These glands are 

 of two kinds, large and small, and probably do not yield one and the 

 same oil. The flowers have a campanulate 2-lipped calyx, and a pale 

 blue and w^hite corolla, the upper lip of which is cmargiuatc and erect, 

 the lower 3-lobed with the central lobe concave and pendulous. The 

 whole plant has a veiy agreeable smell and a strong aromatic taste. It 

 flowers in the early spring. 



Production of Essential Oil— Rosemary is cultivated on a very 

 small scale in English herb-gardens, and though a little oil has been 



occasionally distilled from it, English oil of rosemary is an article prac- 

 tically unknown in commerce. That wdth which the market is supplied 

 is produced in the south of France and on the contiguous coasts of Italy. 

 The plant, which is plentifully found wild, is gathered in summer (not 

 while in flower) and distilled, the operator bein^ sometimes an itmerant 

 herbalist who carries his copper alembic fi'om place to place, erecting it 

 where herbs are plentiful, and w^here a stream of water enables him to 

 cool a condenser of primitive construction. 



Oil of rosemary is also produced on a somewhat large scale in the 

 island of Lesina, south of Spalato in Dalmatia,, whence it is exported by 

 way of Trieste, even to France and Italy, to the extent of 300 to 3o0 



quintals annually.^ 



Some of the French manufacturers of essences offer oil of rosemary 



a 



from the jl^ 



be impracticable on a large scale. The great bulk of the oil iound in 

 commerce is however that distilled from the entire plant. 



Chemical Composition— The peculiar odour of rosemary depends 

 on the essential oil, which is the only constituent of the plant that has 

 afforded matter for chemical research. , „ „ 



^g the plane of polarization to the left ; the otlier, boiling oetween 



200° and 210' C, deposits when exposed to a low temperature a large 

 quantity of camphor Gladstone (1864) found the oil to consist almost 

 ^vholly of a hydrocarbon, C^m^'. This, according to our fP'-^^ts 

 constitutes about 4 of the oil ; it deviates the plane of polarization o 

 the left, whereas a fraction boiling at 200" to 210 C. ^^^viate^^ to t e 

 i-ight. By warming the latter with nitric acid we observed the odoui 

 of common camphor, and may therefore infer that a compound, 

 C^'H^sQ is present in the oil under examination. 



From Montgolfier's investigations (187G) it .v^ould ^PP '^^ f \^* 7 

 Btearoptenc or camphor above alluded to is a mixture of a dextiog^iatt 



and a la^vogyrate substance. 



, ' Unger. Der Rosmarln und seine Vencen- stracted, wit.li a few additions, in Fharm. 

 (fj^'ja m Dalmatien—SitziDifjsherkhle der Jourii. is. {^^i-')^^'^- 

 "^^ner Akademie, Ivi. (1867) 587; ab- 



