296 CUCURBITACE^. 



fruit contains from 200 to 300, are of flattened ovoid form, f^^ oi an 

 inch long by y-^ broad, not bordered. The testa which is hard and 

 thick, having its surface minutely granulated, is marked on each 

 side of its more pointed end by two furrows directed towards the 

 hilum. The seed, as in other Cucurhitacece, is exalbuminous, and has 

 thick oily cotyledons, enclosing an embryo with short straight radicle 

 directed towards the hilum. 



Colocynth fruits are mostly supplied by wholesale druggists, broken 

 up and having the seeds removed, the drug in such case being called 

 Colocynth Fulp or Pith. 



Microscopic Structure — The pulp is made up of large thin- 

 walled parenchymatous cells, their outer layer consisting of rows of 

 smaller cells more densely packed. The tissue is irregularly tra,versed 

 by fibro-vascular bundles, and also exhibits numerous large inter- 

 cellular spaces. The cells contain but an insignificant amount of 

 minute granules, to which neither iodine nor a persalt of iron 

 imparts any coloration. The tissue is not much swollen by water, 

 although one part of the pulp easily retains from 10 to 12 parts of 

 water like a sponge. 



Chemical Composition — The bitter principle has been isolated 

 in 1847 by Hubschmann.^ He observed that alcohol removes from the 

 fruit a large amount of resin. By submitting this solution to distilla- 

 tion, the bitter principle remains partly in the aqueous liquid, partly in 

 the resin, from which the " Colocynthin " is to be extracted by boiling 

 water. The whole solution was then concentrated and mixed with 

 carbonate of potassium, when a thickish viscid liquid separated. 

 Hiibschmann dried it and redissolved it in a mixture of 1 part of strong 

 alcohol and 8 parts of ether. After treatment with charcoal, the sol- 

 vents were distilled and the remaining bitter principle removed by 

 means of water. This on evaporating afforded 2 per cent, of the pulp 

 of a yellow extremely bitter powder, readily soluble in water or alcohol, 

 not in pure ether. Colocynthin is precipitated from its aqueous solution 

 by carbonate of potassium. Colocynthin was further extracted by 

 Lebourdais (1848) by evaporating the aqueous infusion of the fruit 

 with charcoal, and exhausting the dried powder with boiling alcohol. 



Again, another method was followed by Walz (1858). He treated 

 alcoholic extract of colocynth with water, and mixed the solution firstly 

 with neutral acetate of lead, and subsequently with basic acetate of 

 lead. From the filtered liquid the lead was separated by means of 

 sulphuretted hydrogen, and then tannic acid added to it. The 

 latter caused the colocynthin to be precipitated; the precipitate washed 

 and dried was decomposed by oxide of lead, and finally the colocynthin 

 was dissolved out by ether. 



Walz thus obtained about \ per cent, of a yellowish mass or tufts, 

 which he considered as possessing crystalline structure and to which 

 he gave the name Colocynthin. He assigns to it the formula 

 Q5cjj84Q23^ which in our opinion requires further investigation. Colo- 

 cynthin is a violent purgative; it is decomposed according to Walz by 

 boiling dilute hydrochloric acid, and then yields Colocynthein, C^'*H'^*0^^ 

 and grape sugar. The same chemist termed Colocynthitin that part of 



^ Schweizerische Zeitschri/t/ur Pharmacie, 1858. 216. 



