Chap. VI.] DIGESTION. 99 



Olobulin or Crystallin. This substance was kindly prepared for 

 me from the lens of the eye by Dr. Moore, and consisted of hard, 

 colourless, transparent fragments. It is said *" that globulin ought 

 to " swell up in water and dissolve, for the most part forming a 

 gummy liquid; " but this did not occur with the above fragments, 

 though kept in water for four days. Particles, some moistened 

 with water, others with weak hydrochloric acid, others soaked in 

 water for one or two daj's, were placed on nineteen leaves. Most 

 of these leaves, especially those with the long soaked particles, be- 

 came strongly inflected in a few hours. The greater number re- 

 expanded after three or four days; but three of the leaves remained 

 inflected during one, two, or three additional days. Hence some 

 exciting matter must have been absorbed; but the fragments, 

 though perhaps softened in a greater d^ree than those kept for the 

 same time in water, retained all their angles as sharp as ever. As 

 globulin is an albuminous substance, I was astonished at this re- 

 sult ; " and my object being to compare the action of the secre- 

 tion with that of gastric juice, I asked Dr. Burdon Sanderson to try 

 some of the globulin used by me. He reports that " it was sub- 

 jected to a liquid containing 0.2 per cent, of hydrochloric acid, and 

 about 1 per cent, of glycerine extract of the stomach of a dog. It 

 was then ascertained that this liquid was capable of digesting 1.31 

 of its M'eight of unboiled fibrin in 1 hr. ; whereas, during the hour, 

 only 0.141 of the above globulin was dissolved. In both cases an 

 excess of the substance to be digested was subjected to the liquid.*^ 

 We thus see that within the same time less than one-ninth by 

 weight of globulin than of fibrin was dissolved: and bearing in 

 mind that pepsin with acids of the acetic series has only about 

 one-third of the digestive power of pepsin with hydrochloric acid, it 

 is not surprising that the fragments of globulin were not corroded 

 or rounded by the secretion of Drosera, though some soluble matter 

 was certainly extracted from them and absorbed by the glands. 



Ilamatin. Some dark red granules, prepared from bullock's 

 blood, were given me ; these were found by Dr. Sanderson to be in- 

 soluble in water, acids, and alcohol, so that they were prohalily 

 haematin, together with other bodies derived from the blood. Par- 

 ticles with little drops of water were placed on four leaves, three 

 of which were pretty closely inflected in two days ; the fourth only 

 moderately so. On the third day the glands in contact with the 

 lia>matin were blackened, and some of the tentacles seemed injured. 

 After five days two leaves died, and the third was dying; the 

 fourth was beginning to re-expand, but many of its glands were 

 blackened and injured. It is therefore clear that matter had been 



* Watts' ' Diet, of Cheuilstry,' by Schmidt's method, and of this 



vol. II. p. 874. 0.80.5 was dissolved within the 



" [The result was no doubt same time, namely, one hour: so 



due (as I learn from Professor that It was far more soluble than 



Sanderson) to the fact that the that which I used, thon^rh less 



globulin had boen trontod with soluble than flbrin, of which, as 



alcohol In the course of Its prep- we have soen. 1.31 was dissolved, 



aratlon. F. D.] I wl.sh that I had tried on 



" I may add that Dr. Snuder- Drosera globulin prepareil by 



on prepared some fresh Rlobulln this method. 



8 



