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In the following Tables (I') and (II') the numerical values of R, so far as they can be calculated, and of n are given. Table (I') corresponds to Table (I.); (II') to (III.) In Table (II') two values of R bracketed together are given for each term-one for the mean maximum value of I, and the other for the mean minimum value of I. These values of I are taken as 28° 36′ 7′′ and 18° 18′ 31'' respectively.

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Third Report of the Committee, consisting of Dr. BRUNTON, F.R.S., and Dr. PYE-SMITH, appointed to investigate the Conditions of Intestinal Secretion and Movement.

THE first part of the task of your Committee respected the comparative effect on intestinal secretion of various salts locally applied, and the action of other drugs, either mingled with these or injected into the blood, in modifying their action. This was completed in our first Report, in which we gave an account of our experiments on the local action of purgative salts, and stated that atropia has not the same inhibitory effect on intestinal secretion which it has on that of the submaxillary gland.

Secondly, we ascertained last year that the same " paralytic" secretion which Moreau observed in dogs and rabbits occurs under similar conditions in cats; and, further, that this effect is not produced by division of the pneumogastric nerves and cervical sympathetic cord, nor by section of the splanchnics and spinal cord, and that all these sources of nervous supply may be cut off, and both semilunar ganglia extirpated, without paralytic secretion following. We ventured to anticipate that the inhibitory centre sought would be found in the smaller ganglia of the solar plexus. We had also noticed that hyperemia or hæmorrhage of the intestinal mucous membrane does not follow either upon division of the splanchnics or upon extirpation of the lumbar portion of the spinal cord, but frequently occurs when both these operations have been performed together.

This year your Committee have succeeded in proving positively that the conclusion they had reached by the method of exclusion is correct, namely, that the paralytic secretion of Moreau may be produced by extirpation of the smaller ganglia of the solar plexus, including those which are found in the superior mesenteric plexus.

We have also ascertained that removal of these ganglia is rarely followed by hyperemia or hæmorrhage of the intestinal mucous membrane.

Thirdly, turning to the last section of our investigation, the movements of the intestine, we have obtained fairly conclusive evidence that its peristaltic movement (in the cat) is unaffected by irritation of the distal end of the divided splanchnics, but is called forth by stimulation of their proximal part. The conclusions, then, to which your Committee have been led may be thus summed up :

1. Application of various soda and potash salts to the intestinal mucous membrane produces a more or less profuse secretion, that caused by sulphate of magnesia, acetate of potash, sulphate of soda, and tartrate of potash and soda being most abundant.

2. The presence (in the intestine or in the blood) of atropia, morphia, chloral, &c. does not prevent the above action of sulphate of magnesia.

3. The secretory nerves of the intestines have the small ganglia of the solar and superior mesenteric plexuses for their centres; hence secretion is unaffected by section of the splanchnics, the vagi, or the dorso-lumbar part of the cord.

4. Destruction of the lumbar part of the cord, after extirpation of the solar plexus, produces hæmorrhage or hyperæmia of the intestinal mucous membrane, which is absent after division of the splanchnics, destruction of the

semilunar ganglia and solar plexus, or division of the mesenteric nerves themselves.

5. The splanchnic nerves are, as usually admitted, the vasomotor nerves of the intestines, but have no centrifugal fibres to their muscular coats, and can only indirectly affect them by diminishing their supply of blood.

6. The splanchnics are the afferent nerves which regulate peristalsis of the intestine, the efferent stimulus probably reaching its intraparietal ganglia through the lumbar cord and abdominal sympathetic.

The following are the details of the experiments made this year. With those described in our two preceding Reports, they make up a total of more than a hundred, as the basis of the above conclusions.

In the first series we continued and completed the experiments in our last Report, undertaken to ascertain the nervous centre, separation from which produces the "paralytic" secretion of Moreau. Starting from the negative results with which we concluded our research last year, it will be seen that, of the thirteen cases in which we removed the solar or the superior mesenteric plexus, paralytic secretion resulted abundantly in Nos. 1, 2, 3, and 13, where both were removed. The same effect was produced in Nos. 7, 8, and 10, where the splanchnics and semilunar ganglia were left intact, and only the smaller (inferior) ganglia of the solar plexus, with the superior mesenteric offset from it, were excised. In No. 5, and also in No. 14, the paralytic secretion was likewise present, though less abundant. In four cases (Nos. 4, 6, 9, and 11) there was little or none; but in three of these cases the dissection, by which we verified in each case the completeness of the lesion produced, showed that the plexus had only been torn away from the artery without complete excision of its ganglia; and in No. 11 the superior mesenteric plexus was simply cut across, so as to separate it from the semilunar ganglia and splanchnics, with the superior part of the solar plexus. Thus the negative results here, like those of last year's experiments, confirm our present conclusions. In No. 12 there was enough fluid found to fill the loop moderately, but the rest of the intestine was empty: dissection did not show any defect in the previous operation, nor had there been hæmorrhage, diarrhoea, or sickness. It will, however, be noted that in this experiment less time had elapsed than in any of the others (2 instead of 32, 4, 5, or 6 hours); and this fact, taken with the observation of the most abundant secretion having followed the longest period between the excision of the plexus and the animal being killed (see No. 7), may perhaps explain the scanty secretion in this instance.

The concluding series of experiments are on a difficult subject, which has already engaged the attention of Ludwig and his pupils, of Lister, Pflüger, Wundt, Von Basch, and other distinguished physiologists. Whether we are justified in the conclusions which we have drawn we must wait for time to determine, and will only add that we are well aware of the many possible fallacies which attend the inquiry, as well as of the conflicting results of previous investigators.

P.S.-Since this Report was presented (Glasgow, 1876), one of us, who was fortunate in securing the requisite Certificate from the Home Office, has obtained fresh results confirming those of the second series of these experiments.-July 1877.

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1.

2.

Excision of both semilunar gan- 5.........
glia and of the superior mesen-
teric plexus. Two 4-inch loops
ligatured at beginning of je-
junum and at end of ileum.

Same as 1. Superior mesenteric 4
artery accidentally wounded
and ligatured. Diarrhoea before
end of operation. Loops empty
before ligature.

34.

Same as 1

4.

5.

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Upper loop empty; mucous membrane dry. Between the loops 20 c. c. of mucus and serum without bile or blood; mucous membrane moist. Lower loop contained a little of the same. Serous coat congested. Cat vomited shortly before it was killed. Peritoneal congestion of intestines. Duodenum, mucous membrane congested, hæmorrhage into the gut. Upper loop, 5 c. c. of pale opalescent fluidt. Between the loops 40 c.c. of similar but rather thicker fluid, with a few streaks of blood which was accidentally mixed with it. Lower loop, 8 c. c. of thin glairy fluid. Mucous membrane congested throughout.

4......... Upper loop, 8 c. c. of bile-stained fluid. Between loops, 45 c. c. of turbid fluid. Lower loop, & c. c. of clear glairy fluid. Mucous membrane normal.

Mesenteric plexus alone excised. 3-4...... All the loops empty, except a tape

Same as 4. Three 4-inch loops 4.........
in jejunum; middle and lower
ileum tied.

worm in the ileum. Mucous membrane pale. [On dissection, it was found that the operation had been very imperfectly performed, so that the greater part of the plexus was intact.] Duodenum partly contracted, with some fluid contents. Upper loop, 7 c. c. of fluid. Middle, 5 c. c., with small tapeworm. Lower, 4 c. c. (darker) and a tapeworm. Intestine injected outside throughout; mucous membrane in upper loop injected, in the others normal.

* The animals used throughout were cats, and the anaesthetic employed was chloroform. The laboratory assistant, who had been a soldier in India, remarked that this fluid was just like the rice-water stools he had seen in cholera epidemics.

This cat was white, with grey eyes, and was deaf.

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