Not only is formaldehyde a germicide, but it renders innocuous the toxins of tetanus, diphtheria, and many other or ganisms. It is of great value for disin fection of rooms. A 1-per-cent. solution deodorizes It is a far safer agent than corrosive sublimate, because it is not actively poisonous. It will satisfac torily disinfect the hands, will disinfect instruments without dulling them, and is a valuable agent in the steriliiation of catgut. To wash wounds a 2-per cent. solution to be used to irrigate, a solution (Willard). Strong solutions are irritant even to sound tis sues, and are used when we wish a caus tic effect, as in chancroids or poisoned wounds. Vaginal gonorrhoea is benefited by irrigation with a solution of a strength of 1 to 1000, and the cervix can be painted with a 4-per-cent. solution (von Winckel). H. C. Wood (University Med. Mag., June, '97).
As the results of experiments made with fo•malin pastils burned in Sche ring's apparatus, conclusions reached, viz.: that formaldehyde is valuable as a surface disinfectant, and, as it does not injure the most delicate fabrics or papers, it can be used in any such apart ment with safety. It failed, however, to kill germs wrapped in dewspapers, al though forty pastils were used in a room containing 1000 cubic feet of space, the time of exposure being twelve hours. Doty (N. Y. Med. Jour., Oct. 16, '97).
Formaldehyde very satisfactory when using 1 pound of formaldehyde per 1000 cubic feet, or 1 quart of wood-alcohol for the Caine space, and prolonging the actual time of generating the vapor to from one to three hours. Wyatt John ston (Brit. Med. Jour., Dec. 25, '97).
Better results obtained in municipal disinfection by the use of formalin with out any apparatus than heretofore with the various devices. Sheets suspended in the room were simply sprayed with the 40-per-cent. solution through a com mon watering-pot rose-head. A sheet of the usual size and quality will carry from 150 to 180 cubic centimetres of the solution without dripping, and this quantity has been found sufficient for the efficient disinfection of 1000 cubic feet of space. Of course, the sheets may be multiplied to any necessary number.
Culture,. both moist and dry, were ex posed for five hours in these experiments —some in sealed envelopes and others wrapped in three thicknesses of sheets, or folded inside of woolen blankets. Of the former, none showed growth after seventy-two hours' incubation, while the growth was but slight in those wrapped in the b'ankets. Surface-disinfection was thorough, while a much greater degree of penetration was shown in these experiments than that secured by any other method.
The evolution of the gas from the sprinkled sheets is exceedingly rapid, so much so that it behooves the operator to vacate the room within a very few seconds.
After five hours the density of the gas is still so great as to preclude res piration until after doors and windows have been opened some time. Chicago Health Dept. (Jour. Amer. Med. Assoc., Apr. 23, 'OS).
For formaldehyde disinfection 'Aligner has constructed an apparatus consisting of a vessel in which the water is boiled. The steam rises into a reservoir which contains 40 per cent. formaldehyde and 10 per cent. glycerin. This mixture is termed "glycoformal." From this reser voir four pipes pass out into the room. A room of sixty cubic centimetres is so filled with vapor in ten minutes that an electric lamp placed in the centre is no longer visible. All microbes are de stroyed in three hours at the latest. The windows are thrown open for half an hour after the disinfection. Liquid ammonia is then placed in the room in an amount proportionate to the formal dehyde used. The windows are again opened, and thus all smell is got rid of. This method of disinfection can be car ried out by the unskilled. Schlossmann (Berliner klin. Woch., June 20, '98).
Formaldehyde has no penetrating power; it acts best in dry air with high temperatures. It exerts no injurious ac tion on furniture and other objects dis infected. and it is the most expensive of all processes. Symanski (Zeit. f. Hy giene and Infects., Aug. 10, '98).
Attention called to the power of this gas to penetrate the cell-walls of bac teria and destroys them. It retards their growth and destroys invading germs when they attack he respiratory tract. It can only be depended on to destroy pathogenic germs whose structure per mits sufficient penetration to alter their protoplasm, and for this purpose it has no equal as a disinfectant. W. K. Jaques (Merck's Archives, Mar., 1900).
Formalin (a 40-per-cent. aqueous solu tion of formaldehyde) for disinfecting purposes after contagious disease is a cheap and certain destroyer of noxious germs. Basil Klucz,enko (Wiener klin. Woch., Oct. 11, 1900).
Of disinfectants that are efficacious, innocuous, automatic. and inexpensive, the best is formic aldehyde. It forms an odorless compound with ammonia, which becomes useful after disinfection, for removing the smell. It also makes gelatin insoluble, forming a hard, transparent mass. It is antiseptic, dif fusible, and penetrating. Alfred Mar tinet (La Presse Med., April 30, 1902).
Formaldehyde has the property of hardening nitrogenous substances of the nature of gelatin. Cunningham (N. Y. Med. Jour., Apr. 20, '95) makes use of this property in the preparation and ster ilization of catgut. After this method of preparation the catgut can be boiled without destroying it.