tion of the disinfection? On the other hand, it is manifestly improper that it should be detained merely to hold the crew and passengers under observation. First. Because it violates one of the cardinal principles of marine sanitation, inasmuch as it practically brings together in one body persons who at any moment may develop an infectious disease, whereas persons under observation should be as far as possible divided into small groups. Second. Because the outbreak of secondary cases among the passengers or crew held for observation on board would frequently involve the necessity of again disinfecting the ship. It will be easily understood that this may continue indefinitely until the ship is practically a pest-house. This unnecessarily subjects the ship-owner to a loss of his cargo, if it is perishable, and also the loss of the ship's service. A detention of a vessel for this purpose, can hardly be justified on the grounds that a quarantine has no accommodation for the care of persons under observation. Fortunately it is exceedingly rare that the vessel's cargo acts as a medium of contagion; cases of infectious disease develop after the vessel has put to sea and there is no communication between the patient and cargo, the latter being covered with sealed. hatches. It has also been proven that the ordinary cargo does not offer favorable conditions for the propagation of pathogenic organisms; this is particularly so with sugar. It is fortunate that this is the case, as the proper disinfection of a ship's cargo and hold is almost an interminable task. It is, therefore, evident that the first action taken upon arrival of a ship carrying infectious disease is the removal of the sick to the hospital; and, if necessary, of both the passengers and crew to a place where they can be held for disinfection and observation. The ship should then be thoroughly disinfected and allowed to proceed, as further detentiou can add nothing to the protection aiready assured. In this manner we have properly fulfilled our obligations to commerce and the public.

It is generally accepted, I believe, by those who are competent to decide this matter, that steam is the most important disinfectant which we possess, its chief value being due to the uniformity and rapidity of its action and its great power of penetration. At present its application is confined principally to the disinfection of clothing, bedding, and similar textile materials.

For years the value of steam has been appreciated, but further observations were needed to show the degree of temperature and exposure necessary to destroy the organisms of different infectious diseases under given conditions. During the past ten years, valuable information in this direction has been secured as the result of bacteriological investigations. The experiments, however, have mainly shown the effect of steam on the exposed bacilli in the laboratory. Although these experiments are absolutely necessary in forming a standard upon which to work, they do not indicate the degree of temperature needed in treating the materials which are presented at quarantine and other public stations for disinfection. Here it is presumed that the germs are hidden in bundles of clothing, bedding, and packages of different material. Moist heat at a temperature of 150°, Fahr., which experiments have shown will kill the germs of many infectious diseases directly exposed to it, cannot be depended upon to destroy microorganisms confined in bundles, etc. It is therefore essential that we should know the penetrating power of steam or moist heat. Comparatively low moist temperatures have very little penetrating power. This is shown by placing a self-registering thermometer inside. a package which is subjected to a temperature of 150 degrees, Fahr. The thermometer will probably register about 100 degrees, Fahr.a temperature which is not only not germicidal, but is most favorable to the multiplication of micro-organisms, whereas a moist temperature of but 130 degrees or 135 degrees is often destructive to germ life. It is also essential that we should know the resistance to penetration shown by the different articles submitted to treatment. In order to obtain this information a series of experiments have been made during the past year at the New York quarantine station, the results of which have been very satisfactory. The tests have conclusively shown the degree of temperature and exposure necessary under definite conditions to insure thorough disinfection. These results also aid in removing the uncertainty with which steam disinfection has often been applied, both as to the degree of heat required and the length of exposure necessary. As the result of the experiments above referred to, a number of important modifications of the steam apparatus employed have been made. It is now possible to practically dry the clothing, etc., before removal from the steam chamber, so that

it can be worn immediately upon the termination of disinfection, instead of waiting an indefinite period for drying.

The experiments referred to were made with the apparatus now in use on the disinfecting steamer "James W. Wadsworth," which constitutes a thoroughly representative type of the perfected steam disinfecting chamber of the present day. The tests were made by soaking small linen discs in bouillon containing the germs of the Bubonic Plague, diphtheria, and anthrax. The spores of the bacilli of anthrax are particularly hard to kill, and are looked upon as a severe test in any experiment. The germs referred to were made particularly virulent by the inoculation of white mice and guinea pigs, this portion of the work being done at the Bacteriological Laboratory of the Health Officer's Department at Swinburne Island. The infected linen discs were placed inside of bundles of clothing, bedding, carpets, paper, etc., these packages being arranged in a shape similar to those usually presented for disinfection. was found early in the experimental work that paper offered a decided resistance to the penetration of steam-much more than any other material. It was therefore constantly used in the tests. The infected discs were inclosed in packages of paper of different weight and tightly folded; in fact, the amount of paper used exceeded the weight of any wrapping that might be used for packages in transit. Canvas bags containing clothing in the manner used by sailors, heavy mattresses, carpets, and rugs, blankets, sheets, etc., etc., tightly rolled, containing infected discs inclosed, were also tested, the weight of each package being carefully taken in order that the results could be corroborated by second and third tests of exactly the same character, this being done to guard against errors. At the expiration of the test, the discs were at once removed and placed in glass tubes containing bouillon to revive and facilitate the growth of the germs if they were still alive. The discs remained in this condition for a week, or until it could be definitely settled as to the growth of the micro-organisms. Although the results, which are voluminous, cannot be given in detail in this article, it may be said that a summing up of the work showed positively and conclusively that steam at a temperature of 230 degrees, Fahr., with an exposure of 15 minutes will destroy all germs which may be exposed or contained in bundles of clothing, bedding, etc., presented for disin

fection. Self-registering thermometers were in some cases placed inside the packages with the infected discs in order to ascertain the degree of temperature which reached the interior of the package, and it was of great interest and value to know that in all cases a temperature of 150 degrees, Fahr., at least was reached in the largest and heaviest packages of newspapers; whereas in the ordinary package of clothing, bedding, etc., it varied from 175 to 230 degrees, Fahr.; the latter being the temperature of the steam chamber.

These results fully corroborate the laboratory experiments, which have shown that a moist temperature of 150 degrees, Fahr., will usually kill the germs of most infectious disease when directly in contact with them.

It must be understood that the range for practical disinfection with steam is somewhat limited. Materials containing leather, rubber, wood, etc., are permanently injured or destroyed by steam. However, the materials which most frequently carry contagion, such as clothing and bedding, are promptly and effectively acted upon without injury. It is particularly unfortunate that a disinfectant so powerful and reliable as steam should be limited in its practical application, and the urgent need of a reliable agent, which can be used where steam is impracticable, has been fully appreciated. There has been no need of a stimulus to discover a disinfectant which will answer this requirement. It would seem that our hopes in this direction are about to be realized, or, I may say, to a great extent have already been. realized.

In 1868, Professor Hoffman, a German investigator, discovered the disinfecting properties of formaldehyde gas, generated by the oxidation of wood or methyl alcohol. But not until the past three or four years, during which time the experimental work with disinfectants has been most active, has this agent received a thorough investigation. The past year has been prolific in valuable experimental investigations with this gas conducted in the best laboratories of this country and abroad.

In conjunction with the experiments made with steam already described, important tests have been made with formaldehyde gas at the New York Quarantine station. Packages similar to those used in the steam experiments have been exposed under various conditions to this gas. These have been made in con

junction with work done in the laboratory, and although the experimental work is not yet completed, the results are very satisfactory and fully justify us in the conclusion that formaldehyde gas is an agent of pronounced germicidal powers. It also has the rare quality of not injuring the fabrics with which it comes in contact, not in any way affecting the delicate colors found in silks, wall paper, etc. Its penetrating power, however, is not great, but sufficiently so to surely disinfect clothing and bedding, which is unrolled with the surfaces exposed.

Experiments which are now being made with sulphur dioxide or sulphurous acid gas and other disinfectants may yet disclose valuable qualities which are now unknown to us.

During the past year the disinfecting steamer "James W. Wadsworth" has been completed and placed in commission at the New York Quarantine Station; with this it has been possible to make use, in a practical way, of the knowledge gained by the experimental work with disinfectants. The "Wadsworth" is really a portable disinfecting outfit, having the apparatus for disinfection by all the methods now approved. The vessel is always under steam both night and day, and is ready for use at an hour's notice; with it disinfection can be performed at any point in the harbor or connecting waters at any time. The importance of this can only be fully appreciated by those who are directly interested. Before the completion of this outfit it was necessary to remove to the disinfecting station on Hoffman Island in the lower harbor all goods which required disinfection. The time required for transportation involved considerable delay to the ship, particularly in disagreeable or foggy weather. Night disinfection was practically out of the question. Now the weekly mail from Bombay, India, is frequently treated during the night and delivered to the post-office in New York ready for the morning delivery.

Vessels which are usually held for disinfection at the New York Quarantine carry merchandise and no passengers. They come from ports which are known to be infected-generally with yellow fever. These vessels often remain in the infected port some time, and the crew are allowed to visit the shore. Their places of rendezvous on land are generally those in which contagious disease thrives. While the crew may not themselves become infected, it is possible for them to act as a medium of contagion, VOL. CLXV.-NO. 489.

14