CLOVES 



67 



tube, but is perhaps most correctly interpreted as the solid lower 

 portion of the ovary (Tschirch), crowned by four, thick, divergent 

 calyx-teeth of a similar colour, from the centre of which arise four, 

 paler, brown, unexpanded, imbricated petals. After soaking in water 

 for twenty-four hours the petals can be removed, and they will be 

 found to enclose a large number of stamens bending over a stiff erect 

 style arising from a depression in the centre of a small disc. Just 

 below the disc is the two-celled ovary with its numerous ovules ; it 

 can be found by cutting the clove either longitudinally or transversely. 



The lower part of the ovary is solid and fleshy, spongy near the 

 centre. It contains, especially near the periphery, a large number 

 of oil-glands, visible, when 

 the transverse section is ex- 

 amined under the lens, as 

 dark shining points or small 

 cavities. Similar glands can 

 be seen both in the calyx- 

 teeth and petals ; in the 

 latter they appear as trans- 

 lucent dots by transmitted 

 light. 



Cloves are strongly aro- 

 matic and have a pungent 

 aromatic taste. Good cloves 

 should be plump and heavy, 

 have a bright, reddish-brown 

 colour, sink in water, and 

 exude oil when indented with 

 the finger-nail. 



FIG. 38. Clove (Eugenia caryophyllata). 



A, clove cut vertically, showing calyx, 

 corolla, stamens, pistil, and ovules ; 

 near the margin oil-glands ; magnified. 



B, fruit (mother clove), natural size. 



C, the same, cut vertically and magnified. 



D, embryo, natural size. (Luerssen.) 



Constituents. Cloves con- 

 tain a large quantity of 

 volatile oil, a considerable 

 proportion (13 per cent. 



Peabody, 1895) of tannin, which has been identified as gallotannic 

 acid, and a colourless, odourless, crystalline substance, caiyophyllin. 

 They yield from 5 to 7 per cent, of ash. 



The most important of these constituents is the volatile oil, and 

 the value of the drug is determined chiefly by the amount 

 of oil that it contains, good cloves yielding from 15 to 20 per 

 cent. 



The chief constituent of the oil (not less than 85 per cent.) is eugenol, C 10 H 12 O 2 , 

 a colourless liquid with an odour of cloves, boiling at 253 ; a terpene (caryo- 

 phyllene), aceteugenol, a-methylfurfural, dimethylfurfural, methyl salicylate 

 and other bodies are also present. The amount of eugenol present can be 

 approximately determined by shaking a measured quantity of the oil with 



