Cuar. VL DIGESTION. 113 
two leaves with the smaller cubes only to a moderate 
degree. The jelly on all four was by this time lique- 
fied, and rendered very acid. The glands were 
blackened from the aggregation of their protoplasmic 
contents. In 46 hrs. from the time when the jelly 
was given, the leaves had almost re-expanded, and 
‘completely so after 70 hrs.; and now only a little 
slightly adhesive fluid was left unabsorbed on their 
discs. 
One part of chondrin jelly was dissolved in 218 
parts of boiling water, and half-minim drops were 
given to four leaves; so that each received about 54, 
of a grain (135 mg.) of the jelly; and, of course, 
much less of dry chondrin. This acted most power- 
fully, for after only 3 hrs. 30 m. all four leaves were 
strongly inflected. Three of them began to re- 
expand after 24 hrs., and in 48 brs. were completely 
open; but the fourth had only partially re-expanded. 
All the liquefied chondrin was by this time absorbed. 
Hence a solution of chondrin seems to act far more 
quickly and energetically than pure gelatine or isin- 
glass; but I am assured by good authorities that it 
is most difficult, or impossible, to know whether 
chondrin is pure, and if it contained any albumi- 
nous compound, this would have produced the above 
effects. Nevertheless, I have thought these facts worth 
giving, as there is so much doubt on the nutritious 
value of gelatine; and Dr. Lauder Brunton does not 
know of any experiments with respect to animals on 
the relative value of gelatine and chondrin. 
Milk.—We have seen in the last chapter that milk 
acts most powerfully on the leaves; but whether this 
‘s due to the contained casein or albumen, I know not. 
Rather large drops of milk excite so much secretion 
(which is very acid) that it sometimes trickles down 
