of high rank, well up in the eighties, whose sudden death at home was announced only twelve days later. This I take to be a good illustration of the narrowness of the path along which many of our visitors walked that day. A little more heat, or a little more humidity, would have meant much more harm to our old soldiers. We may well be glad to have had so little to do, but to have been ready for any emergency is also something to be proud of. The disposition of our sanitary corps was this:-In the procession: the first of our automobiles carried the Commissioner of Health, Dr. Samuel G. Dixon, in charge, accompanied by the Chief Medical Inspector, Dr. B. Franklin Royer, and the Chief Visiting Dispensary Nurse, Miss Alice M. O'Halloran. The other automobile carried the Medical Inspector of Dispensaries, Dr. Thomas H. A. Stites, and a nurse, Miss Butler. On the departmental ambulance was the Associate Chief Medical Inspector, Dr. Charles J. Hunt, with a nurse, Miss Shellenberger, and two orderlies. After the parade all these were on duty in the Capitol, or about the stand outside, or with the ambulance stationed near the north door. In the Capitol our Consulting Surgeon, Dr. George B. Kunkel, was stationed in the main office of the Division of Sanitary Engineering with one of the nurses from the parade and a couple of orderlies, ready to be summoned for any surgical emergency. In the north corridor, near at hand, were placed several cots, ready for immediate use, in charge of the Chief of the Division of Distribution of Biological Products, Dr. J. Moore Campbell, and the Assistant Chief Medical Inspector, Dr. John J. Mullowney, assisted by the nurses Miss Lewis and Miss Roth. The waiting room near the main entrance, equipped with two cots and several reclining chairs, was in charge of the Assistant to the Commissioner, Dr. Joseph W. Warren, assisted by the nurse Miss Doyle. Outside, on the stand or near at hand, were also the State Registrar, Dr. Wilmer R. Batt, the Medical Director of the Mont Alto Sanatorium, Dr. Fred. C. Johnson, and the County Medical Inspector, Dr. Clarence R. Phillips. As orderlies served Messrs. Braugher, Butterworth, Forsythe, Heister, Miller, Myers, Seiders, and Shindler. Very soon after the beginning of the war in Europe it became evident that a most serious interference with our supplies for disinfection purposes was to be expected. The generally acceptable method for the disinfection of rooms which have been occupied by cases of communicable diseases involves the development of formaldehyde gas from its aqueous solution. This process requires the use of a certain quantity of the permanganate of potash. The amount of this substance needed for the fumigations made by our Health Officers is enormous. In the year 1913 our storekeeper had to supply 1851 "units" of disinfectants each including twenty-two pounds of the permanganate, making a total supply of over forty thousand pounds for that year. The price of this chemical immediately started to soar and there was even reason to fear that the supply might be altogether cut off unless the war came to a speedy end. I at once began to look about for some other substance which could replace the permanganate of potash, at least until the price should fall again within reasonable limits. With the aid of our consulting chemist experimental studies were undertaken to find a satisfactory substitute. Our search was more rapidly successful than we had dared hope, and we were soon able to announce that the dichromate of sodium could replace the permanganate of potash in disinfection outfits such as are used by us and elsewhere. The development of the gas by the use of the dichromate proved to be even more rapid than when the permanganate is employed. It was also found desirable to add a certain proportion of sulphuric acid to the solution of formalde hyde. As soon as the new method was fully demonstrated to be prac ticable, I arranged for its utilization in our disinfection work, and made it known by the following brief publication in the widely read Journal of the American Medical Association (Sept. 19, 1914; vol. lxiii, p. 1025). A SUBSTITUTE FOR POTASSIUM PERMANGANATE TO LIBERATE FORMALDEHYDE GAS FROM A WATER SOLUTION. Samuel G. Dixon, M. D., LL. D. Commissioner of Health, Commonwealth of Pennsylvania. Almost immediately after the declaration of war by Germany I requested the department's chemist, Mr. Charles Lawall, to proceed at once to find a substitute for potassium permanganate that would liberate formaldehyde gas from a water solution for the purpose of disinfecting. In the literature no mention of any other specific substance was found except in an English patent application (4885, J. S. C. I., 1908, 915), where a combination of sodium bisulphite and formaldehyde solution was acted on by potassium permanganate or other peracid salt, and the fumigation formula: Formaldehyd, 37 per cent. solution, .2 parts. .1 part. Eight ounces of this solution are used to 1 pound of lime to 1,000 cubic feet. Dr. George Rosengarten suggested sodium dichromate as a cheap oxidizing agent, and hydrochloric acid to increase its energy. Lawall found on experimenting that sodium dichromate was more energetic and satisfactory in the presence of sulphuric acid. Numerous experiments, confirmed by calculations on the relative oxidizing power of potassium permanganate and sodium dichromate, and also working out the optimum proportion of sulphuric acid, led to the conclusion that the following proportion gave the best results, which are in every way comparable to those with potassium permanganate: Sodium dichromate 10 ounces avoirdupois. Saturated solution of formaldehyde gas 1 pint. The sulphuric acid and formaldehyde gas form a stable solution. This after it cools should be poured over the crystals of sodium dichromate spread out in a thin layer over the bottom of a vessel having ten times the capacity of the volume of ingredients used. It was found that the process was more rapid than with potassium permanganate. This would necessitate the health officer's withdrawing promptly from a room in which the process had been started. Lawall, when working on a small scale, found in every case a corrosive residue. Much to his surprise the residue in ten minutes was dry and pulverulent, and a galvanized bucket which had been used showed very little effect of the reaction after washing out with soap and water. He made a quantitative determination by both the permanganate and dichromate methods to determine the amount of volatile material given off and found that in each case it approximated eight ounces avoirdupois (or about half the weight of the formaldehyde solution taken.) As formaldehyde solution contains between thirty-five and forty per cent. of gaseous HCOH and as the residue in each case was found to be dry and particularly devoid of odor after two hours' standing, Lawall concluded that the two methods are equally effective from the quantitative standpoint. Formaldehyde solution and commercial sulphuric acid may be kept in stock and shipped in the mixed form (ten parts of formaldehyde solution and one part sulphuric acid, both by volume). Lawall found the solution would be perfectly safe. The solution would have to be handled with more care than the plain formaldehyde on account of the acid making it slightly corrosive. The elimination of mosquitoes is a problem of perennial interest to sanitarians. This can be accomplished only by the destruction of the larvae or pupae which are found on the surface of streams or may occur in any open receptacle containing water. In streams and ponds certain small fish are known to be active destroyers of the larvae and other forms of aquatic animals are believed to be similarly efficient. For some time I have looked upon the duck as likely to be an important aid in this matter. Observations made on my farm have confirmed this opinion and led me to present my conclusions in a brief article in the Journal of the American Medical Association (Oct. 3, 1914; vol. lxiii, p. 1203) which I reprint below. THE DUCK AS A PREVENTIVE AGAINST MALARIA AND YELLOW FEVER. Samuel G. Dixon, M. D., LL. D. Commissioner of Health, Commonwealth of Pennsylvania. The duck is one of the greatest known enemies of the mosquito, and therefore of yellow fever and malaria. It has possibly one of the widest geographical ranges of any of the birds. It is even found in the Arctic and Antartic regions; also in Australia, where bird life is so peculiar. After trying the ability of fish to devour larvae and pupae of mosquitoes, with varied success, I built two dams near together on the same stream, so that each would have the same environment for the breeding of mosquitoes. Each covered nearly 1,400 square feet. In one, twenty mallard ducks, Anas platyrhynchos, were permitted to feed, while the other was entirely protected from water fowl, but well stocked with goldfish, Carassius auratus, variety americanus. The one in which the ducks fed was for several months entirely free from mosquitoes, while the pond protected from ducks and stocked with fish was swarming with young insects in different cycles of life. To the infested pond ten well fed mallard ducks, Anas platyrhynchos, were then admitted, and as they entered the pond they were first attracted by the larval batrachians, tadpoles. They, however, soon recognized the presence of larvae and pupae of the mosquito and immediately turned their attention to these, ravenously devouring them in preference to any other foodstuff present. At the end of twentyfour hours no pupae were to be found and in forty-eight hours only a few small larvae survived. The motion of the water, made by the ducks, of course drowned some of the insects-what proportion cannot be estimated. For some years I have been using ducks to keep down mosquitoes in swamps that would have been very expensive to drain, but I never fully appreciated the high degree of efficiency of the duck as a destroyer of mosquito life until the foregoing test was made. In the work of Howard, Dyar, and Knab, entitled "Mosquitoes of North and Central America and the West Indies," will be found* an essay on the destruction of the mosquito and house fly by Mr. William Beutenmueller, who expresses the opinion that aquatic birds could be used for the purpose of destroying mosquito larvae. Mr. William Lockwood of Boston, an artist, who made a hobby of raising aquatic fowl, also expresses an opinion that the spoonbilled duck is particularly adapted to the destruction of mosquito larvae resting on the surface of the water. Mr. McAtee of the Biological Survey found mosquitoes in the gizzard of the mallard duck. While other birds, fish, spiders, batrachians, arthropods, and reptiles are all enemies of the mosquito, none of them have such a wide geographical range and a capacity of devouring large numbers of the larvae and pupae on land and water as the duck. Ducks can be used in ponds and swamps, both open and in jungles, and can be driven from place to place. Not only can they be generally used to keep down mosquito life but they also furnish a delicious and valuable foodstuff. The practice of utilizing the newspapers for the dissemination of information concerning the work of the Department has been continned. In weekly "Talks" I have briefly discussed questions pertaining to public and domestic sanitation and in simple language have commented on the conduct of life from the point of view of one who would encourage sane living among his fellows. The press notices which have been brought to my attention and the very numerous letters which have come to me indicate that these talks have been widely read and approved. The monthly "Health Bulletins" bearing the year 1914 as a date. are as follows: No. 54, January. The Waters of Pennsylvania. An Address before the State Board of Agriculture. No. 55, February. The Preparation of the Biological Products distributed by the Pennsylvania Department of Health. This Bulletin was an extensive revision of the Bulletin bearing the same title and originally issued in October, 1911. L. 0. Howard. H. G. Dyar, and Frederick Krab:-Mosquitoes of North and Central America and the West Indies, Washington, Carnegie Insitution, 1913, 1, 178. |