252 ROSACEA. 



enumerated, but in the reformed editions of 1746, 1788, and 1809, the 

 French Prune {Prunumi Gallicum) is specially ordered, its chief use 

 being as an ingredi&nt of the well-known Lenitive Electuary; and this 

 fruit is still held by the grocers to be the legitimate prune. The same 

 variety is regarded in France as the prune of medicine. 



Description — The prune in its fresh state is an ovoid drupe of a 

 deep purple hue, not depressed at the insertion of the stalk, and with a 

 scarcely visible suture, and no furrow. The pulp is greenish and rather 

 austere, unless the fruit is very ripe ; it does not adhere to the stone. 

 The stone is short (yV to y^^r of an inch long, yV to ^ broad), broadly 

 rounded at the upper end and slightly mucronulate, narrowed some- 

 what stalk-like at the lower, and truncate ; the ventral suture is 

 broader and thicker than the dorsal. 



The fruit is dried partly by solar and partly by fire heat, — that is 

 to say, it is exposed alternately to the heat of an oven and to the open 

 air. Thus prepared, it is about 1| inches long, black and shrivelled, but 

 recovers its original size and form by digestion in warm water. The 

 dried pulp or sarcocarp is brown and tough, with an acidulous, 

 saccharine, fruity taste. 



Microscopic Structure — The skin of the prune is formed of 

 small, densely packed cells, loaded with a dark solid substance ; the 

 pulp consists of larger shrunken cells, containing a brownish amorphous 

 mass which is probably rich in sugar. This latter tissue is traversed 

 by a few thin fibro-vascular bundles, and exhibits here and there 

 crystals of oxalate of calcium. By perchloride of iron, the cell walls, 

 as well as the contents of the cells, acquire a dingy greenish hue. 



Chemical Composition — We are not aware of any analysis 

 having been made of the particular sort of plum under notice, nor that 

 any attempt has been made to discover the source of the medicinal 

 property it is reputed to possess. Some nearly allied varieties have 

 been submitted to analysis in the laboratory of Fresenius, and shown 

 to contain saccharine matters to the extent of 17 to 35 per cent., 

 besides malic acid, and albuminoid and pectic substances.^ 



Uses — The only pharmaceutical preparation of which the pulp of 

 prunes is an ingredient, is Confectio Sennce, the Electuarium lenitivuni 

 of the old pharmacopoeias. The fruit stewed and sweetened is often 

 used as a domestic laxative. 



Substitute — When French prunes are scarce, a very similar fruit, 

 known in Germany as Zwetschen or Quetschen, is imported as a sub- 

 stitute.*^ It is the produce of a tree which most botanists regard as a 

 form of Prunus doriiestica L., termed by De Candolle var. Pruneau- 

 liana. K. Koch,^ however, is decidedly of opinion that it is a distinct 

 species, and as such he has revived for it Borkhausen's name of Prunus 

 ceconomica. The tree is widely cultivated in Germany for the sake of 

 its fruit, which is used in the dried state as an article of food, but is 

 not grown in England. 



The dried fruit differs slightly from the ordinary prune in being 



^ Liebig's Ann, der Ghemie, ci. (1857) ^ This was especially the case in the 



228. winter of 1873-74. 



•' Dendrolofjie, part i. (1869) 94. 



