Richardson impregnates filter paper with iodine by pouring over it a solution of iodine in amyl hydride. The volatile solvent almost immediately evaporates, leaving the paper charged with iodine. A few such sheets hung up in a sick room in various places cause the air to become slightly charged with iodine vapour, whereby disinfection is rapidly effected. If a higher charge be required, it may be obtained by burning a few papers after the fashion of spills. For highly infectious cases, where more rapid action is required, the solution of iodine in amyl hydride is disseminated through the room in the form of spray, a glass spray-producer being employed, as metal would be rapidly corroded. If much solution has been used, care must be taken not to bring a light into the room, as the mixture of air and amyl hydride vapour is explosive in certain proportions. In obstinate cases - where a strong persistent smell is to be got rid of, for instance - the room must be closed up for some time after filling it with spray, in order to give the iodine time to act on the noxious matters. (Medical Times and Gazette.)

Eckstein finds that bleaching-powder is the most effective disinfectant for privies, urinals, etc, inasmuch as it rapidly decomposes hydrogen compounds, such as ammonia, sulphuretted hydrogen, etc. It is conveniently applied in a bag made of parchment paper, through which the disinfectant slowly passes by osmosis. Comparative experiments made in the author's house (where at least 100 persons use the closets daily) gave the following results: -

(1)2 lb. sulphate of iron (green vitriol) dissolved in water prevented the production of smell for 2 or 3 hours, and had wholly lost its preservative action in 12 hours.

(2) Sulphate of copper in solution produced the same result.

(3) 2 lb. solid sulphate of iron or sulphate of copper acted as a disinfectant for full two days.

(4) A mixture of iron and copper sulphates and carbolate of lime (2 lb. in all) only remained active for 2 days.

(5) Solution of sulphurous acid lost its action quickly: it was perceptible to the respiratory organs for an hour.

(6) Crude carbolic acid filled the house with a peculiar tarry odour for 2 days. This was so powerful that it could not be determined whether the smell of the faecal matter was decomposed or merely hidden by a more powerful odour.

(7) 2 lb. sulphate of iron in a parchment-paper bag only became active after 2 hours, and remained active for full 3 days, at the end of which time the bag contained a muddy liquor destitute of smell.

(8) 2 lb. good commercial bleaching powder in a parchment-paper bag became active in 2 hours, and remained efficacious for full 9 days, without in the least affecting respiration or smell.

(9) Crude permanganate of soda disinfected immediately, but only lasted for 1 day. In a parchment-paper bag the same quantity lasted 2 days.

From these results the author concludes that bleaching-powder in a parchment-paper bag acts the longest and the most energetically, and is therefore the best disinfectant of those tried.

The merits of sulphate of iron (copperas or green vitriol) for disinfecting purposes have been described thus: - It is not a hygienic disinfectant, since it does not destroy the lower forms of life. As a remedy, therefore, against the spread of epidemic diseases, which spread by the dissemination of the germs of such minute organisms, it is quite useless. As a chemical disinfectant, however, for the suppression of offensive odours, affecting the question of comfort rather than health, it is an excellent agent. Wherever the ordinary system of a walled reservoir for holding excremental matters is in vogue, and where, as is generally the case, the reservoir is but seldom emptied, the air of the vicinity, especially during periods of low barometer, will be charged with pungent and offensive odours. These may be effectually checked by the periodical addition of the sulphate in solution in water.

Valmagini of Vienna alleges that binoxide of manganese is a valuable and potent disinfectant. He has found that ozone is not only present in this mineral, but that it is continually regenerated. Hence he considers the mineral well adapted for destroying putrefactive gases.

Lead chloride is declared to be an excellent disinfectant, absorbing and neutralizing various organic vapours. It may be prepared by precipitating 65 oz. lead nitrate with 23 2/5 oz. sodium chloride, yielding 553 oz. dry lead chloride. It is very slightly soluble in cold water, 1 gal. not holding more than 1/4 oz.; hot water dissolves more, but the salt crystallizes out again on cooling. For closets, 1/2 lb. of the salt may be suspended in 1 gal. water, but it is better hot.

Certain inconveniences and disadvantages attending the use of carbolic acid spray in dressing wounds have led to a general search for acceptable substitutes.

One of the most promising is the use of substances which are volatile as well as of antiseptic nature, such as eucalyptol, cajeput, terebene, and peppermint, by means of which a wound may be kept, if necessary, in an antiseptic atmosphere, not merely while being dressed, but at all times. At the late annual meeting of the British Medical Association, A. W. Mayo Robson described a series of experiments made by him to test the efficiency of atmospheres charged with such volatile antiseptics in preventing the development of life in putrescible fluids, the results being exceedingly encouraging. Flasks of sterilized hay infusion suspended in large wide-mouthed open jars, into which a little eucalyptus oil, cajeput oil, or the like, had been poured, remained clear; while flasks of the same infusion, briefly exposed to ordinary air and then covered with cotton wool, began to lose clearness and to scum over within a few hours. Altogether the results were thought to indicate that at ordinary temperatures air saturated with vapours of the class named was fatal to the germs of bacteria and micrococci, and probably also to the germs of fevers and other infectious diseases.