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light of an experiment. "A small quantity of the dejecta of a cholera patient was known to have been washed into a vessel containing water, the mixture after being exposed to the heat of the sun for one day, was swallowed by 19 men on the following morning; within three days five of these were affected with cholera."

(394) Modern Experiments on Animals with Cultivations of the Comma Bacillus, &c.

Nicati and Rietsch, injected directly into the duodenum of dogs and guinea-pigs cultivations of the comma bacillus, they induced a disease very much like cholera. This experiment was repeated by Babes, Flugge, and Watson Cheyne, and the results confirmed. At first Nicati and Rietsch ligatured the bile duct, but subsequently this was not found necessary. Koch also repeated this experiment and declared that out of 18 guinea-pigs into which he had injected the comma bacillus into the duodenum, 13 had died of cholera. At the same time control experiments were not omitted, and cultivations of a number of other pathogenic organism were injected into the duodenum of guinea-pigs; all the control animals lived. In 1885 Koch announced that he had succeeded in reproducing the disease in the guinea-pig without opening the animal's abdomen. He had studied the digestive process in the guinea-pig and found that the stomach reaction was always acid; this acidity had probably destroyed the commas when the latter were given by the mouth. To overcome this, he had injected into the stomach a solution of soda; in this way the commas were made to pass along into the small intestine, nevertheless, there was mostly failure. This he ascribed to the rapid peristalsis of the first portion of the rabbits' intestines, the commas were hurried on, before they had time to multiply. He found that coloured foods passed from stomach to coecum in a few minutes. To overcome this, he dosed the animals with opium (the opium being injected into the peritoneal cavity). "I apply," says Koch, “opium in the form of tincture, in the dose of 1 c.c. to every 200 grms. weight of the animal. After this dose there follows in a very short time deep narcosis, after which the animal is as lively as before. With a combination of soda solution and cholera broth,

and after injection of opium tincture, experiments were made on 35 guinea-pigs; of these 30 died of cholera. The symptoms during life and the appearances after death were identical with those found in guinea-pigs which had received duodenal injections." 1

Dr. Neil Macleod 2 has repeated and extended these experiments of Koch. In thirty-four experiments on guinea-pigs with cultivations of comma bacilli, all were successful in producing a choleralike disease; in twenty-one of the animals the result was fatal. Eleven control animals treated exactly in the same way, but receiving sterilized broth, recovered, and showed no symptoms. Three animals also receiving soda solution alone, were in no way affected.

From one of the animals that died after a dose of cholera material the small gut contents were collected in a sterilized vessel and injected in doses of 2 c.c. into the stomachs of two other animals. These two animals died and the contents of their small intestines were used in the same way, and so on through ten generations. Of twenty-one animals thus treated two recovered, nineteen died. The dose varied from 5 to 2.5 c.c.

The post-mortem appearances in the guinea-pigs experimented on by Macleod are thus described :-"The blood was fluid, thicker and darker than natural; the tissues of the thoracic and abdominal walls were markedly dry; the small intestine was throughout distended, congested, and paralyzed-looking, and occupied a much larger proportion of the abdominal cavity than usual. The coecum was distended with fluid or semi-fluid contents. If the animal had died early the fluid was not quite clear in the small gut, there being present traces of food, still the watery character was very manifest and mucous flakes were abundant. If the animal had died on the second or third day, no food remains were to be seen, and the fluid in the small gut was the counterpart of the typical cholera stool in man. In either case the comma bacilli were demonstrated microscopically and by cultivation as in man. While the organism in the broth injected could be frequently counted in a microscopic field, in a drop of the small bowel contents from an animal having received such broth, the bacilli might be so numerous that counting them without dilution of the fluid examined 1 Ber. Klinische Wochenschrift, Sept. 21, 1885. 2 Public Health, 1888, vol. i. p. 322.

was an impossibility. On floating the bowel on water the stripping of the epithelium could be well demonstrated."

The conclusions arrived at by Dr. Neil Macleod and Walter J. Milles, F.R.C.S. Eng., in their able research, are as follows:-1st, the comma bacillus of Koch is invariably present and associated with certain changes in the small intestine, in cases of Asiatic cholera; 2nd, there is no evidence to show that it is a normal inhabitant of the human alimentary canal, and therefore no proof for the assertion that it is a result of the disease. 3rd, the means used to introduce the comma bacillus into, and those used to lessen the peristalsis of, the small intestine of the guinea-pig cannot be regarded as causing appearances like those of Asiatic cholera, or as causing the death of the animal, far less a mortality of over 60 per cent.; 4th, pure cultivations of the comma bacillus introduced into the stomach under the precautions described, are pathogenic to the guinea-pig; 5th, injected with similar precautions, the contents of the ileum from those animals killed by injections of pure cultivations of the bacilli, act in the same manner as pure cultivations of that organism; 6th, the organism multiplies in the small intestine of the animal, and there are associated therewith changes similar to those in man in Asiatic cholera."

(395) Propagation of Cholera by Water and Otherwise.

In the brief history of cholera in England, sufficient examples have been given as to the propagation of cholera by water. Koch considers that the cholera contagium is in all cases swallowed, the commas may be in the water or may be in food, but it must be swallowed; he would consider the possibility of it being propagated by sewer gas problematical, and that it can be blown about as dust and breathed in that form, would be negatived by the experimentally ascertained fact that drying is fatal to the bacillus. In respect therefore to the propagation of cholera in other ways than by swallowing the contagium in food and drink, the history of the introduction of cholera into Southampton as described by the late Dr. Parkes in 1866 is full of interest.1 On the 10th of June, 1866, the P. and O. steamship Poonah arrived from Alexandria, Malta, 1 Ninth Rep. of the Med. Officer of the Privy Council.

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and Gibraltar, having on the preceding day lost a man from cholera ; the cause of the outbreak was attributed to foul water taken in at Gibraltar; the history clearly shows that the severe diarrhoea prevailing on board the steamship was confined to a certain section of the crew who drank the water from a particular tank, and this water was found on analysis to be much polluted. However this may be, it is certain that eight or ten people suffering from "choleraic diarrhoea were landed in the town and dispersed in various quarters, and that their dejections passed into the sewers."

There were doubtful cases of cholera on June 12th, June 15th, and July 6th in Southampton, but the disease definitely and unmistakably broke out from July 6th to the 13th up to the evening of the 17th no less than thirty-five to thirty-seven deaths had occurred. By the 4th or 5th of August the epidemic was virtually over.

Dr. Parkes considered that the outbreak probably introduced by the Poonah had no connection with the water supply of Southampton. "The whole of Southampton is supplied from a town reservoir; the supply is continuous; there are no cisterns. If the water was the cause it must have affected the town generally; there are nearly 50,000 people in Southampton, and there were only 320 cases of cholera scattered over nearly three months. It is impossible to suppose that 49,700 people who used the water could have escaped had the water been bad." ... "The disease was certainly worst in the most unhygienic parts of the town, but was not confined to these, for good houses in airy situations in the low part of the town suffered and some of the worst localities remained free."

After a very careful consideration of all the possible causes, Dr. Parkes was inclined to accuse the sewer system. "Almost all the town is sewered, but unfortunately on a bad principle, a very large network of sewers being provided towards the outlet in order to act as a reservoir during certain periods of the tide. There is thus a great stagnancy during several hours of the day, and indeed at some periods it is probable that there is very little flow even for long periods. The ventilation is very imperfect, being provided for by gratings in the road, and as these give off offensive effluvia, they are continually stopped up with pieces of wood by the inhabitants of the neighbouring houses. The consequence is

that the gases are thrown back upon the houses and force their way through the very imperfect traps."

From causes detailed in the original report, the sewers at the time of the Poonah's arrival were in a particularly clogged and offensive state, and the sewage pumping at the western station had been discontinued. "In the beginning of July the pumping of the western shore sewer into the outlet sewer was recommenced." . . . "All the immense mass of sewage from the western sewers was raised and then poured down an open conduit into the outlet sewer. Tons and tons of sewage were thus daily pumped up, and frothing and agitated by this churning were poured like a cataract down the open channel for some 8 or 9 feet. The effluvia disengaged from this quantity of seething sewage was overpowering. It spread all over the neighbourhood, and was bitterly complained of in the adjacent houses. The effect, however, would not be confined to them; the cloud of effluvia thus thrown up must have extended far beyond the point where it was detectable by smell. The occurrence of some early cases of cholera in clean, airy houses near this pumping station was the first thing that called attention to it, and it was then found that diarrhoea was beginning to prevail in several of the adjacent houses. There was no local cause to account for these attacks except the great effluvia thus disengaged." But the most striking point in the history is when a closed iron pipe was substituted for the open conduit and carbolic acid largely used as a disinfectant, there was an immediate diminution in the cholera outbreak; the alteration took place on the 19th of July, and Dr. Parkes says, "On the 24th of July the worst was over."

It is therefore only reasonable to believe that the incidences as to time and place were not accidental, but that the state of the sewers and the cloud of spray and effluvia at the pumping station had a very definite connection with the Southampton cholera epidemic of 1866.

(396) Propagation of Cholera by Clothes Soiled with the Discharges.

There are also numerous cases on record in which those who have washed the undisinfected linen of cholera patients have been attacked with cholera, and the following incidents are types

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