FRUCTUS ECBALLII. 293 



3-celled and contains numerous oblong seeds lodged in a very bitter 

 succulent pulp. The fruit when ripe separates suddenly from the 

 stalk, and at the same moment the seeds and juice are forcibly expelled 

 from the aperture left by the detached peduncle. This interesting 

 phenomenon ^ is due to the process of exosmosis, by which the juice of 

 the outer part of the fruit gradually passes through the strong contractile 

 tissue which lines the central cavity, imtil the pressure becomes so 

 great that the cell gives way at its weakest point. This point is that 

 at which the peduncle is articulated with the fruit; and it is the 

 sudden and powerful contraction of the elastic tissue when relieved 

 from pressure that occasions the violent expulsion of the contents of 

 the central ca\4ty. 



For the preparation of the officinal elaterium, the fruit has to be 

 employed while still somewhat immature, for the simple reason that it 

 would be impossible to gather it so as to retain its all-important juice 

 if left till quite ripe. When it is sliced longitudinally as in making 

 elaterium, some of the juice is expelled by virtue of the endosmotic 

 action already described, as can easily be seen on examining the con- 

 tracted lining of the sliced fruit. 



Pereira observes ^ that if the juice of a fruit is received on a plate of 

 glass, it is seen to be nearly colourless and transparent. In a few 

 minutes however, by exposure to the air, it becomes slightly turbid, and 

 small white coagula are formed in it. By slow evaporation, minute 

 rhomboidal crystals make their appearance : these are elateHn. 



Hot, dry weather favours the development of the active principle of 

 the drucj.^ 



Microscopic Structure — The middle layer of the fruit is built up 

 of large somewhat thick-walled cells, traversed by a few fibro- vascular 

 bundles. The former abound in small starch grains, and also contain 

 granules of albuminous matter. 



Chemical Composition — The experiments of Clutterbuck (1819) 

 proved that the active properties of the elaterium plant reside chiefly, 

 though not exclusively, in the juice that surrounds the seeds ; and it is 

 to this juice and to the medicinal product which it yields, that the 

 attention of chemists has been hitherto directed. 



The juice obtained by lightly pressing the sliced fruits is at first 

 greenish and slightly turbid. After having been set aside a few hours, 

 it yields a deposit, which has to be collected on calico, rapidly drained 

 with gentle pressure between layers of bibulous paper and porous bricks, 

 and dried in a warm place. The substance thus obtained is theElaterium 

 of pharmacy.^ The method recommended by Clutterbuck* involves no 

 pressing. The juice of the sliced fruit is saved, and the pulp, scooped 

 out by the thumb of the operator, is thrown on a sieve and slightly 

 washed with pure water. From these liquors, elaterium is deposited. 



1 I have not yet seen Yule's paper on the at Mitcham in the very fine summer of 



dehiscence of this fruit in the Joitrn. of 1868, I was told that the people occupied 



Anat. and Physiologif, 1877. The struc- in slicing the fruits had never sufiFered so 



ture of the testa of the seed is explained severely from their work as in that year. — 



by Fickel, in the Botanische Zeitung, 1876. D. H. 



77-i. — F. A. F. * There is a genus of Cucurbitacece founded 



- Elem. of Mat. Med. iL (1853) 1745. by Linnaeus, also called Elaterium. 



' Having had to procure elaterium fruits ^ Lond. Med. Repository, xiL (1820) 1. 



