bodies with the plague, Simond crushed a number of fleas taken from plague rats and making a mixture with some sterilized water inoculated other rats, which soon developed the plague. To further establish the fact that simple contact or vicinity was insufficient, without inoculation, to develop the plague, he resorted to the following experimenting. Beneath a large glass jar he placed a plague-infected rat with fleas, with a healthy rat enclosed in a small cage to prevent any actual contact. The well rat sometimes developed the plague and died. But if the plague rat was previously cleansed of its fleas, the well rat remained perfectly well.

3rd. The same observer noted that a dead plague rat was dangerous in inducing the disease in others in proportion to the length of time which had elapsed since its death, as a rat for a certain time dead, would be entirely rid of fleas, and no longer a source of danger, whereas a recently dead, but still warm rat would still be covered with fleas and dangerous in that proportion. It was furthermore noticed that persons taken down with the plague are more often afflicted with the bubonic manifestation in the groin than elsewhere, thus showing that the seat of infection, or rather of the inoculation, was in the lower extremities, the localities most liable to be attacked by fleas. This is also taken to account for the more rapid spread of such epidemics among the Southern Asiatics and in those epidemic plague centers in Arabia, where the populations are mostly accustomed to wander about barefooted and with equally as bare legs,—the dirt floor of the habitations in those regions assisting to maintain a home for the fleas.

In many respects the plague bacillus resembles in its viability that of typhoid fever, although it diametrically differs in its method of infection. Like the bacillus discovered by Eberth in 1880, it thrives in filth and in unsavory surroundings, and in a like manner it as speedily dies either in sunshine or in fresh pure air. In water its existence is brief, and gaseous disinfectants act upon it more quickely than they do on most other disease germs. Weak solutions of corrosive sublimate, carbolic acid, lysol, lime, or of mineral acids easily kill it. On the other hand Hankin states that the germ has lived for seven months in a sealed tube.

The evidences, however, obtained in laboratory experiments and experience, and those gathered from actual facts as they are

found to exist in the wider world outside of the bacteriologic laboratory, are often most conflicting. The bacillus of the plague seems to have the power of accommodating itself in various regions, and to its surroundings in the most exasperating and inconsistent manner. It thrives in the dry arid deserts of Arabia, just as it does in the low marshy regions of the Nile, or in the frozen regions of northern Russia as it does in the hot soil of India. It is a most capricious and incomprehensible bacillus, and while its habits are not always understood or its methods fully explicable, we can logically apply what lessons we may learn from the more or less conclusive experiments and observations of Simond and other observers in the field of inoculation as a cause.

The German commission appointed to investigate the nature of the plague and to test the sparophitic properties of its bacillus, join in the view of those who believe that inanimate objects play but little if any part in its dissemination. This commission decided that the infective period of the bacillus did not survive beyond seven days.

Accepting the rat and flea medium of dissemination as an established fact-if not the sole one, most certainly a very prominent one-the next question that presents itself is the evasion or destruction of the rat as a disease generating cause in man. The rat pest as a nuisance has been more or less of a worry ever since the hardy brown rat coming from the East gradually drove his black brother out of existence and, unterrified by oceans, boldly crossed the seas to our own shores. Millers, warehousemen, butchers, shipping men and many others, have long attempted their local extermination, and it is from these and their successes, and with the assistance of the bacteriologist and the cultivator that we must, somehow, learn how to deal with the rat in its relation to the plague.

How this can in one way best be accomplished, can be learned by studying a leaf from the current industrial and agricultural history of Thessaly in Greece. The rats in that region are so prolific-one female giving birth annually to as many as five or six litters of from six to twelve young-that the wheat and other grain crops have been more than once completely ruined by the rodents.

Various means were adopted to attempt their extermination. One of these consisted in flooding the infected districts-a

method not practicable on all fields by reason of the inaccessibility of sufficient water. The bisulphide of carbon, so effectual with a solitary gopher in the United States, proved too laborious as well as expensive a method owing to the great numbers of burrows to be treated. Various attempts to poison them were also failures in the main and were abandoned.

In 1892 the ravages of these animals became so destructive that the Government felt called upon to treat the question in all of its seriousness. After a consultation between the minister or director of agriculture and the minister of the interior, it was decided to solicit the assistance of Professor Loeffler of Greifswald in Germany, who had, through his laboratory work, evolved a serum productive of a specific rat plague which was very fatal. The professor repaired to Athens with a supply of his lymph and from thence proceeded to Thessaly and began his operations in the village of Bacrena in the vicinity of Larissa, the lymph being used on pieces of bread which were greedily eaten by the rats. In eight days the disease appeared in the fields and spreading rapidly, destroyed enough rats to save the grain crops. This procedure has been employed with great success every year, and Thessaly has saved her agricultural resources.

Another method which may be employed to destroy rats on board ships or in cellars, as well as in barns in their underfloor spaces and in their burrows in basement walls is described in the following from a late Literary Digest.

"The destruction of rats by carbonic acid, especially in case of epidemics, is recommended by Paul Apery, a druggist in Constantinople, so we are told by the Zeitschrift fur die gesammte Kohlensaure-Industrie. Apery describes at length the advantages of this method, which was discovered by accident. In November of last year, on board the Polis Mytilini,' a death from plague occurred while the ship was in the harbor of Trieste. When the vessel was disinfected, it was noted as very surprising at first that there were no rats on board. But when several barrels of molasses (the contents of which were in a state of fermentation) were removed, a quantity of dead rats were found. It was evident that they had been killed by the carbonic acid that streamed from the casks. Apery recommends therefore, that nuts, cheese, fat, etc., be placed in the hold of an infected ship to attract the rate. Then by means of a cylin

der of liquid carbonic acid the gas may be turned among the vermin. By reason of its great specific gravity, the gaseous carbonic acid will remain in the bottom of the hold. When the rats have been killed, the fumes can be cleared off either by means of ordinary ventilation, or, if necessary, by an air-pump; after which the dead rats can be disinfected and removed. The advantages claimed by Apery for this method are the following: 1. When the carbonic acid gas is poured thus on the rats, they have no longer the strength to escape, but die where they are. 2. It is the cheapest possible means of getting rid of them. 3. The carbonic acid has no odor, is not inflammable, and destroys nothing. 4. The height to which the gas is allowed to rise in the hold can be easily controlled. 5. The gas penetrates into all holes and crannies. 6. No evil effects remain, and the space can be used immediately after ventilation. To some extent this method can be used also in cellars and houses.”

The advice given to ships when at docks to place funnels on their hawsers to prevent the escape.or entrance of rats should be supplemented by each port or quarantine station being furnished with a carbonic acid generator with which a ship's hold could be flooded with the gas. The practice of fumigating suspected ships now in vogue, with men stationed in boats to kill the rats as they escape overboard, is not as safe or as effectual a safeguard as the carbonic acid which overcomes them and dispatches them whenever it meets them. While much remains undetermined concerning the origin or mode of contagion of the disease or of its nature we can safely follow out such indications as promise some protection.

DEFECTIVE METABOLISM IN RELATION TO THE MUCOUS MEMBRANES.

By H. D'ARCY POWER, L. S. A. Eng., L. R. C. P. Ire., Professor of Principles and Practice of Medicine, College of Physicians and Surgeons, San Francisco.

Among the many problems that daily solicit solution, none are more common, and at the same time difficult, than the departures from health dependent on deranged metabolism. Patients who persist in remaining morbidly thin, and patients who decline to be other than morbidly stout; patients with a nervous system that is never thoroughly awake, and patients

with a nervous system that cannot sleep; the indolent and the neurasthenic are alike victims of a perverted cellular chemistry. Metabolism may suffer as a result of deficient nutrition, of defective or excessive oxidation, of a morbid condition of the trophic centers, on which local nutrition is dependent, or from fundamental or temporary defects of certain tissues only. Thus we meet with individuals whose muscular systems never attain the normal; others, such as our ever increasing army of neurotics, with an initial defect in the nerve protoplasm, and others who show weakness in their serous or mucous membranes. I am not about to enter into a discussion of the whole subject of morbid metabolism and its cure, and am here only concerned with the cases last mentioned in which, for reasons not often discernable, the mucous membranes and their contained glands, suffer excessive, diminished, or perverted activity.

It has been my fortune to come across not a few of such cases, and therewith has grown a belief of the importance of the part such local defects play in the general well being. One of the first cases to which my attention was drawn was that of a female patient who, after a severe attack of pelvic cellulitis, developed a morbid condition of the buccal mucous membrane which was dry and studded with discrete masses of hypertrophied epithelium; the condition was not due to fungi, and the gastro-enteric symptoms present made it evident that the alimentary canal was similarly affected, as was also the vagina. The condition persisted in spite of treatment for over three weeks, and the patient was rapidly succumbing to the associated anorexia, when the exhibition of ammonium benzoate entirely cured it in as many days. The drug was given in the belief that we were dealing with a dyscrasia affecting the metabolism of all the mucous tissues. Less severe cases have since come under my observation, and have done well under the influence of the ammonium benzoate, or of potassium chlorate. Speaking of the potassium chlorate, there is an all too prevalent idea that its utility is limited to the treatment of mucous surfaces; but as a matter of fact, it affects in a powerful manner the general nutrition, often causing rapid increase in weight and improvement in well being. As we have perverted action of the mucous membranes so may we have simple excessive or diminished activity. Not long since I had a case of ptyalism in which the buccal mucous membrane, as well as the true salivary glands

VOL. XLIII.-52.