256 ROSACE.E. 



o-rown in Holland under precisely similar circnmstances, in each month 

 of the year. The results proved that the product obtained during the 

 winter and early spring was weaker in the acid in the proportion of 

 17 to 24, 28, or 30, the strongest water being that distilled in July and 

 August. This chemist found that a stronger product was got when 

 the leaves were chopped fine, than when they were used_ whole. 

 According to Christison,^ the buds and very yoimg leaves yield ten 

 times as much essential oil as the leaves one year old. We have 

 ascertained that leaves collected in January when they were thoroughly 

 frozen yielded a distillate containing about ten times less of hydrocyanic 

 acid than in summer. The product obtained from the leaves collected 

 in January, but previously dried for several days at 100" C (212 I.), 

 still proved to contain both essential oil and hydrocyanic acid. 



The unwounded leaves of the cherry-laurel in vigorous vegetation 

 have been shown by our friend Prof. Schaer, not to evolve naturally a 

 trace of hydrocyanic acid, though they yield it on the slightest 

 puncture. We are ignorant of the mode of distribution in the uving 

 tissue of the lauro-cerasin, and of the substances causing its decompo- 

 sition, and how these two bodies are packed so as to prevent the slightest 

 mutual reaction. The leaves may be even dried at 100° C- and 

 powdered without the evolution of any odour of hydrocyanic acid, but 

 the latter is at once developed by the addition of a little water ; on dis- 

 tilling its presence is r.vnvA<-7 "K^r Tv^oana a-P nil f.bfi usual tests intheiirs 

 drops of the product. 



means 



sential 



Besides the substances concerned in the production of the essenti 

 oil, the leaves contain sugar which reduces cupric oxide in the cok , 

 small quantity of an iron-greening tannin, and a fatty or ^^ax) 



substance. 



(1868) 



w 



yielded i 



crystals ; these quickly reduced cupric oxide, losing their bitterness. 



(1877) isolated from 



others, Phyllinic acid, a crystalline powder melting at 170° 0. j 



Uses— The leaves are only employed for making ^herry-i 

 water {A qua Lauro-cerasi), the use of which in England is genei ; 

 superseded by that of the more definite hydrocyanic acid. 



FLORES KOSO. 



Kosso 



Botanical Origin—Sagenia abyssinica Willd. (Brayera tMit^^«^- 

 niinthica Kunth), a handsome tree growing to a height oi ^ ^^ 

 found throughout the entire table-land of Abyssinia at an ^leva .^ 

 3,000 to 8,000 feet above the sea-level.^ We have ' never ^^^\^. 

 growing in any botanic garden. The tree ' is remarkable for ^^J^, ^^^^a 

 dant foliage and fine panicles of flowers, and is generally P 

 about the Abyssinian villages, 



. fjliibiti'* 

 Dhpmmtory, 1842. 592. from Madagascar to the 1 aris r. 



i he French section of the International of 1878. , Trimen, '^^'''^■ 



Atncan Association contrihuted Kousso ^Y\g. in Bentley and rnui 



Planfs, part 5 (1876). 



