educational but are stimulative and encouraging by showing what has been done, what is now doing and what can be done by well directed effort in the way of preventing and stamping out entirely many of the infectious diseases that have no right to exist in any civilized community.

Though the publication of the BULLETIN entails a great deal of additional work upon the Secretary the expense is comparatively light and is entirely within the appropriation.

FORMALDEHYDE.

Every community and especially boards of health are interested in any and all measures tending to decrease the danger from contagious and infectious disease.

One of the most important of them is that of disinfection whereby the germs of disease are destroyed. Hitherto dependence has been had largely upon heat, and vapors generated from various substances, principally sulphur. The latter has been used principally owing to its accessibility and convenience, but results have been unsatisfactory.

1.

Because it is unreliable as a germicide.

2. It injures fabrics and wall paper.

3. It is peculiarly obnoxious to respiration, rendering rooms in which it is used, unfit for use for considerable time. Sanitarians and hygienists were therefore ready and pleased to receive the announcement of the discovery by Trillat, in 1890, of a process for evolving a gas (Formaldehyde CH,O) from methylalcohol, which will destroy disease germs without damage to rooms, injuring fabrics, destroying colors, or tarnishing metals, except iron and steel. Possessing the highest germicidal properties, it has rapidly advanced to the front rank as an antiseptic, and become the ideal disinfectant. Its vapor almost instantly penetrates every crevice of a room, floors, bed clothing, wardrobes, closets, rendering innocuous all infectious materials. The accidental inhalation of its vapor, or even drinking the solution will not result injuriously. All of which commends it for use in every day life. Exhaustive experiments in every direction have been made, and the universal decision is that formaldehyde is the disinfectant par excellence.

IN SCHOOLS.

Schoolrooms may be daily disinfected during the periods of epidemics, and thus enable the schools to be kept open. The generation of formaldehyde vapor in the rooms will cause complete disinfection of all of the contents of the rooms, such as desks, books, wall maps, and blackboards. The cloakrooms containing cloaks, hats, coats, rubbers, comforters, etc., of the pupils may be filled with formaldehyde vapor and thus disinfected while the pupils are at their lessons, rendering transmission of disease by this means improbable. Even the water closets may be rendered inodorous and free from contagion by this method.

IN THE HOME.

In the home the use of formaldhyde is accompanied by the highest advantages. The sick room may be disinfected by means of the generator, every piece of furniture being acted upon by the gas set free in the room. The nurse and relatives of the patient are thus greatly protected, and when convalescence from diphtheria, scarlatina or other contagious or infectious diseases sets in, the occasional visitor will run very little chance of carrying away any contagion. It is also of the highest advantage in the disinfection of rooms with their contained furniture when visitors, who may be suspected of having been exposed to contagious disease, have departed. Many persons innocent of knowledge or intent of conveying disease have carried contagion to families where they have visited. The instant sympathy which is shown to a stricken family causes well meaning friends, neighbors or relatives to visit the family and patient to offer services before the nature of the illness is known and wide distribution of contagious disease results. The innumerable epidemics of the world's history furnish abundant examples of diseases spread by this means. The convalescing patient is also a source of contagion in most cases, as the bacteria of infectious and contagious disease linger with or near the recovering patient, ready for a new subject. In fatal cases the contagion may be conveyed to the funeral attendants and visitors and multiply the disease and death. The ease or readiness with which every article that is used in the sick room, such as tableware, medical necessities, bed pans, etc., etc., may be disinfected without injury by formaldehyde gas, makes it the ideal disinfectant for home use. Not less notable is the fact that it will not injure or

change the most delicate tints of wall paper, drapery, painting, fresco work, nor blacken or tarnish metallic instruments or silverware.

IN PUBLIC OFFICES, HOTELS, ETC.

Equally important to the people is it that the sanitary condition of the home shall be extended to public offices, hotels and business houses.

Jails, prisons, station-houses and work-houses require frequent disinfection to preserve the health of inmates. Formaldehyde vapor is here the best antiseptic, inasmuch as it is a deodorant as well as a disinfectant, and sweetens the atmosphere while destroying the bacteria. If the atmosphere be impregnated with formaldehyde gas it will penetrate every crevice of floor, wall, ceiling or closet and destroy lurking disease germs. Its economy also fits it for a wholesale use in

such places.

IN LIBRARIES, PUBLIC AND CIRCULATING.

Formaldehyde is the only practical disinfectant for books. Books of circulating libraries acquire all the disease bacteria that are present in the homes of the borrowers, since it is usual for patients to be provided with books from circulating libraries in order to pass away the hours of convalescence, time when disease breeding bacteria are still present. Perhaps the nurses or attendants of the sick are not less guilty of borrowing books while surrounded by the infectious or contagious atmosphere of the sick room. Many epidemics have been shown to have been promoted in this manner.

Mr. E. G. Horton, working in the Laboratory of Hygiene of the University of Pennsylvania, has written an interesting and instructive article on the disinfection of books by formaldehyde obtained by the evaporation of a concentrated solution. In the work several questions presented themselves which were essentially as follows: Under ordinary conditions can books be disinfected by formaldehyde? What is the smallest proportion of the vapor to the air which will effectively sterilize in a limited time-as twenty-four hours? What is the shortest exposure that will suffice? Is a decrease in the amount of the vapor present counter-balanced by an increase in the length of time of expose?

The main conclusions reached were to the effect that books could be disinfected in a closed space by formaldehyde. The

disinfection is rapid, when the atmosphere is rich in formaldehyde, the effect produced in the first fifteen minutes is practically equivalent to that observed after twenty-four hours. Prolongation in the time of exposure does not counter-balance a dilution of the formaldehyde. In cases where the disinfection had been incomplete, the vitality of the organisms had been so weakened that they survived, only if transferred in a few hours to media suitable for their development. The use of formaldehyde is not detrimental so far as observed in any manner to the books, nor is it objectionable to the operator beyond temporary irritation of the nose and eyes, somewhat similar to that produced by ammonia.

The frequency with which second and third cases of scarlet fever appear in houses that have been disinfected by the inspectors of sanitary authorities, says The Lancet, causes grave doubts as to the efficiency of the procedure usually adopted, despite its official sanction. Stripping the walls, lime washing walls and ceilings, and scrubbing woodwork and floor boards with soap and water are indeed effectual enough, and to these when thoroughly done we are disposed to ascribe any successful results rather than to the more technical process of so-called disinfection by sulphur fumes, which is little better than a superstitious rite or incantation shorn of the religious character it had in the mind of Ulysses when he "fumigated" the halls desecrated by the massacre of his wife's suitors after removing the corpses and washing away the blood with a promptness that precluded all thought of other than moral pollution. But in the light of bacteriological experiments dry sulphurous acid fumes, whether generated by burning sulphur or carbonic sulphide, or, as has of late become the fashion, by opening cylinders of the compressed gas, are for all practical purposes useless. The gas would act as a fairly powerful germicide on articles or fabrics previously saturated with water, but its bleaching action precludes its employment in this way with colored materials, carpets or curtains, and it is as what is called an "aërial disinfectant" that it holds its ground in popular esteem. But ærial disinfection is an absurdity; no one wants to purify the foul air, which is easily enough removed by simple ventilation. In disinfecting a room the true aim is to kill the germs contained in dust on ledges or in the crevices between the boards, or adhering to the walls and other surfaces, and the dry sulphurous gas is powerless for this work.

Sulphurous acid fumes as a disinfectant have undoubtedly proved a failure, but we can reach and sterilize concealed infectious matter in rooms only by means of a reliable gaseous germicide. This we have in formaldehyde, as the following reports will testify:

In Hospital, July 25th, Dr. H. W. Jones gives an account of some of the latest work done with formaldehyde as a disinfectant of rooms and hospital wards. The experiments of Drs. Roux and Trillat have shown that the dust on walls could be completely sterilized. As regards penetrating power, the results are no less conclusive. Thus Dr. Bosc of Montpelier found that staphylococci concealed in the pocket of a coat, and colon baccilli placed under a mattress folded on itself, were rendered absolutely sterile.

Roux and Trillat have discovered an ingenious method of testing this penetrating power. This action of formaldehyde on gelatin is to render it insoluble; to make use of this property as a test little cubes of glass are coated with liquefied gelatin. When the gelatin has set these are placed in various positions in the room which is being sterilized, and after the process is completed examined by immersion in boiling water. It is found that on those cubes which have been exposed to the action of formaldehyde the gelatin coating is insoluble.

Another test, used by the same observers, depends on the power which formaldehyde possesses of converting aniline reds into blues or violets. Bits of cloth dyed with fuchsin can be used in this way as tests, or a combination of this and the gelatin test can be used, the gelatin being dyed with fuchsin before the glass cubes are coated.

Roux and Trillat demonstrated that animals can live in an atmosphere that has been treated by formaldehyde vapor. This is done by washing first with a solution of ammonia and then with sulphuric acid. This treatment would have no chemic action on any oxides of carbon that might have been formed during the disinfecting process, so that it may be taken as proved that the process is unattended by any risk for the evolution of carbonic acid. There is yet another point which has been brought out by these experiments with formaldehyde. It has been proven by Pottevin and also by Roux and Trillat that to obtain the best results a temperature of thirty-five degrees C. is necessary. Still, it was found by actual experiments