G. GASPAKEINI ON THE RIPENING OE EIGS. 







perfectly ripe, some split, the others increased greatly and ap- 

 proached maturity. We are quite ignorant how the carbolic acid 

 acts, whether all is the result of the mere act of growth, or the 

 ripeniug of the free part is owing to its immediate action. If we 

 take a thin slice of the receptacle, commencing with the cuticle, 

 and expose it upon glass to the action of the acid in question, it 

 attacks and destroys suddenly the contents of the innermost 

 cells, which are the most tender, dilates them, and forms a 

 mucous stratum, so as to make it appear that they are decom- 

 posed ; but on washing them we see that they are still entire. 

 The effect is gradually less towards the cuticle, which becomes 

 more rigid. A little lamina, taken from the parenchyma of the 

 inferior surface of the leaf, having hairs or nervelets, submitted 

 to the action of the carbolic acid, undergoes the following 

 change : — The contents of the more tender cells become more or 

 less decomposed, the chlorophyll resists, but changes its green 

 tint into a yellowish red ; the younger cellular membrane becomes 

 puffed up ; the cuticle remains unaltered ; the hairs swell a little, 

 without bursting. The crystals (cystoliths) at first appear more 

 distinct, then by degrees, but after many hours, are dissolved. 

 No notable action takes place on the membrane of the spiral or 

 fibro- cellular vessels. 



Formic acid is less active than carbolic ; it likewise dries up the 

 part on which it is spilled, and makes it brown, though slowly ; 

 the scales become rigid ; but the dead part does not become 

 mouldy in the course of ten days. Out of twenty-four re- 

 ceptacles, on the tenth day, three were ripe, seven nearly so, 

 seven had increased in size, the others remained as they were at 

 the commencement of the experiment. 



Tartaric acid brought to perfect maturity tw T enty-five fruits, be- 

 longing to four varieties, when applied to the mouth; and in a short 

 time (that is to say, within the space of a week) five among them 

 were split. The emcaey and speed of the operation of this acid 

 does not admit of any doubt, the experiment having been repeated 

 many times with the same effect. Lowered with a very little 

 water, and applied to the mouth of the fruit, it first softens the 

 scales and then dries them, promotes, for some distance from the 

 place where it spreads, the issue of some little drops of milk, 

 which afterwards condense into globules of a gummy aspect, on 

 which a little mould frequently springs up. Among the many 

 substances which promote the ripening of the fig, this acid alone 



