338 OF DIGESTION AND NUTRITIVE ABSORPTION. 



when these were submitted to its action at a constant temperature of 100 

 (which is about that of the stomach), and were frequently agitated. The 

 solution appeared to be in all respects as perfect as that which naturally takes 

 place in the stomach ; but required a longer time. This is readily accounted 

 for, when we remember that no ordinary agitation can produce the same effect 

 with the curious movements of the stomach ; and that the continual removal 

 from its cavity of the matter which has been already dissolved, must aid the 

 operation of the solvent on the remainder. The following is one out of many 

 experiments detailed by Dr. Beaumont. "At llj o'clock, A, M., after having 

 kept the lad fasting for 17 hours, I introduced a gum-elastic tube, and drew off 

 one ounce of pure gastric liquor, unmixed with any other matter, except a 

 small proportion of mucus, into a three-ounce vial. I then took a solid piece 

 of boiled recently-salted beef, weighing three drachms, and put it into the 

 liquor in the vial ; corked the vial tight, and placed it in a saucepan filled 

 with water, raised to the temperature of 100, and kept at that point on a 

 nicely-regulated sand-bath. In forty minutes, digestion had distinctly com- 

 menced over the surface of the meat. In fifty minutes, the fluid had become 

 quite opaque and cloudy ; the external texture began to separate and become 

 loose. In sixty minutes, chyme began to form. At 1 o'clock, p. M., (digestion 

 having progressed with the same regularity as in the last half-hour), the cel- 

 lular texture seemed to be entirely destroyed, leaving the muscular fibres loose 

 and unconnected, floating about in fine small shreds, very tender and soft. At 

 3 o'clock, the muscular fibres had diminished one-half since the last exami- 

 nation. At five o'clock they were nearly all digested ; a few fibres only 

 remaining. At 7 o'clock the muscular texture was completely broken down, 

 and only a few of the small fibres could be seen floating in the fluid. At 9 

 o'clock every part of the meat was completely digested. The gastric juice, 

 when taken from the stomach, was as clear and transparent as water. The 

 mixture in the vial was now about the colour of whey. After standing at rest 

 a few minutes, a fine sediment of the colour of the meat subsided to the bottom 

 of the vial. A piece of beef, exactly similar to that placed in the vial, was 

 introduced into the stomach, through the aperture, at the same time. At 12 

 o'clock it was withdrawn, and found to be as little affected by digestion as that 

 in the vial ; there was little or no difference in their appearance. It was 

 returned to the stomach ; and, on the string being drawn out at 1 o'clock, p. 

 M., the meat was found to be all completely digested and gone. The effect of 

 the gastric juice on the piece of meat suspended in the stomach was exactly 

 similar to that in the vial, only more rapid after the first half-hour, and sooner 

 completed. Digestion commenced on, and was confined to, the surface entirely 

 in both situations. Agitation accelerated the solution in the vial, by removing 

 the coat that was digested on the surface, enveloping the remainder of the meat 

 in the gastric fluid, and giving this fluid access to the undigested portions."* 

 451. Many variations were made in other experiments, some of which 

 strikingly displayed the effects of thorough mastication in aiding both natural 

 and artificial digestion. The following table exhibits some of the most inte- 

 resting results of these experiments. It may also be regarded as affording 

 some approximation to the relative solubility of different kinds of aliment ; but 

 a more accurate series of experiments, conducted with an express view to the 

 determination of the quantity of albumen formed in each case, is still required 

 for this purpose. The proportion of gastric juice to aliment, in artificial diges- 

 tion, was generally calculated at one ounce of the former to one drachm of the 

 latter. In several of the experiments, the limited extent of the powers of the 

 solvent was very evident ; its character thus corresponding exactly with that 

 of ordinary chemical agents. 



* Experiments 2 and 3, of First Series. 



