mentally retarded, 11 per cent feeble-minded, 4 per cent possibly feeble-minded, 3 per cent homosexual, and 6 per cent with psychopathic personalities. The unusually high percentage of feeblemindedness observed in this school is due to the number of feebleminded among the delinquents sent by the juvenile courts of Maryland and the District of Columbia. The former has inadequate facilities for the care of the feeble-minded, the latter none. SANITARY SURVEY OF PUBLIC-SCHOOL BUILDINGS, MARLBORO On request of the State board of health, a sanitary survey was made of the public-school buildings and grounds of Bennettsville, Clio, McColl, and Tatum, Marlboro County, S. C., April 30 to May 2, 1917. It was found that at all of the schools the grounds, though of ample size, were without apparatus and were utilized but little for regulated outdoor physical exercises. The heating and ventilation systems of the schools needed improvements, the toilet, privy, and lavatory facilities were unsatisfactory, and due regard for hygienic principles had not been observed in the equipment, decoration, and illumination of classrooms. Specific recommendations were made to the authorities. MENTAL AND PHYSICAL STATUS OF CHILDREN IN PELLAGROUS COMMUNITIES. In connection with pellagra studies in certain cotton-mill villages of Spartanburg County, S. C. (see p. 29), physical and mental examinations of the children in these communities were commenced (at Cowpens, Apr. 13, 1917) for the purpose of comparison with children of nonpellagrous communities, and to study the influence of dietary conditions on nutrition in children in pellagrous communities. By June 30, 1917, 2,534 children had been examined. For the purposes of publication, data from this investigation will be compiled in a report with similar data from other localities. COOPERATION WITH MARYLAND STATE BUREAU OF LABOR AND STATISTICS. In cooperation with the Maryland State bureau of labor and statistics, tests of mental development of children applying for permits for employment in industrial occupations were made by Surg. J. A. Nydegger from January 25 to May 15, 1917. RURAL SANITATION.1 INTENSIVE COUNTY SURVEYS. Special studies of and demonstration work in rural sanitation were continued under the direction of Surg. L. L. Lumsden. The sanitary surveys of Floyd County, Ga., Greenville County, S. C., Obion See also "Disinfection of human excreta" in the report of the Hygienic Laboratory, p. 67. County, Tenn., and Tuscaloosa County, Ala., referred to on page 67 of the last annual report, were completed during the year, and sanitary surveys were begun in Clay County, Miss., Cumberland County, Ill., Hill County, Tex., Okmulgee County, Okla., and Mason County, Ky. The work was completed in Clay and Cumberland Counties, but was still in progress in Hill, Okmulgee, and Mason Counties at the end of the fiscal year. The officers in immediate charge of the surveys were: Asst. Surgs. W. H. Slaughter, J. G. Townsend, K. E. Miller, H. C. Yarbrough, R. E. Wynne, and W. C. Witte, and Asst. Epidemiologist F. E. Harrington. The plans for these surveys have been generally the same as in previous years, namely, visits to as many individual homes as possible; reinspections of a certain number of homes in different neighborhoods to find out the sanitary improvements carried out; delivery of lectures on sanitation; inspections of public buildings; securing the cooperation of civic organizations and prominent citizens; and, finally, surveys of the incorporated towns in the county and making specific recommendations to the authorities which will bring about sanitary disposal of excreta, prevention of fly breeding, and protection of food and water supplies. The ultimate purpose of the surveys is to awaken in rural communities an individual and communal interest in public-health questions which will in turn lead to an improvement in sanitary conditions and the maintenance of an efficient local health agency. The scope of the surveys during the past fiscal year is indicated in the following table: Data as to sanitary surveys of counties made during fiscal year 1917. Marked progress in sanitary improvements was made in each of the counties in which the work was conducted. The results obtained in Hill County, Tex., as indicated by an inspection of the work made recently by Epidemiologist A. W. Freeman, form a good example of this progress. Dr. Freeman found that in the county seat, Hillsboro, the work of sanitation was practically complete and that nearly all the privies in the town had been rebuilt and made fly proof. In the other towns of the county, with one exception, the same results have been obtained. The ordinary open back insanitary privy, in practically universal use in the county prior to the survey, has been replaced by an excellent type of sanitary privy, properly screened and ventilated and capable of easy and satisfactory cleaning. Suitable and efficient scavenger systems have been devised for the towns, and the danger of fly-borne typhoid fever has been reduced to a minimum. In the rural districts, also, improvement has been marked, and approximately one-third of the rural homes have already made improvements in their sanitary appliances. There has been real and permanent improvement in the general health administration of the towns and a very successful campaign of general education in sanitary matters. A full report of the work and its results in the 15 counties surveyed since the beginning of the special studies of rural sanitation in 1914 is in course of preparation. On the basis of experience gained in this work, a bulletin relating to a sanitary privy system for unsewered towns and villages was prepared by Surg. L. L. Lumsden and published as Public Health Bulletin No. 89. SPECIAL STUDIES. Besides the intensive surveys of counties some other special studies have been begun during the year and are still in progress. Asst. Surg. R. E. Wynne, assisted by a sanitary engineer of the Public Health Service, is making a sanitary survey of a group of rural towns in Wyoming, Prof. C. W. Stiles, Prof. E. B. Phelps and Surg. L. L. Lumsden with a number of assistants are making field and laboratory studies with a view of determining the feasibility of chemical treatment of privy contents so as to make the matter safe from a sanitary standpoint without decreasing its fertilizer value. In this phase of the work the main field studies are being made in New Hanover County, N. C., and the bacteriological and chemical work is being done at the Hygienic Laboratory. Asst. Surg. K. E. Miller, acting as whole-time county health officer, is making a practical study of county health work in Edgecombe County, N. C. (See p. 43.) INVESTIGATIONS OF POLLUTION OF STREAMS. Extensive studies of the problems associated with the pollution of navigable waters were first begun by the service in 1913. Preliminary surveys were made of the Potomac River in January and work started on the Ohio River in July. The Ohio studies have been carried on with headquarters at Cincinnati, under the direction of Surg. W. H. Frost. ORGANIZATION. At the beginning of the 1917 fiscal year the following personnel was assigned to duty for stream-pollution studies at the headquarters' laboratory at Cincinnati: Five medical officers, 1 pharmacist, 1 epidemiologist, 1 special expert (biologist), 5 sanitary engineers, 3 sanitary bacteriologists, and 15 attendants. At the end of the year the force had been much reduced by transfers, resignations, and special details for health problems arising out of the military situation. The personnel then comprised 1 pharmacist, in temporary charge, 1 sanitary engineer, 4 sanitary bacteriologists, 1 special expert (biologist), I sanitary chemist, and 8 attendants, including the force engaged in special studies of industrial wastes. OHIO RIVER. As mentioned in previous annual reports, the object of these studies has been not only a study of pollution conditions as existing in the Ohio River, but more especially a quantitative analysis of the various factors concerned in the pollution and self-purification of streams in general. In addition to extensive and intensive laboratory investigations of the degrees and types of pollution, including exhaustive bacteriological, chemical, and biological (plankton) examinations, consideration was given to the coordination of these findings with the general status of public-health conditions in the communities situated on the main river and its tributary drainage systems. Comprehensive sanitary surveys have been made of all cities, towns, and communities of any importance located on the Ohio River watershed, with special reference to the effects of stream pollution upon public health. In computing the sanitary status of the communities thus studied on the basis of possible influence of stream pollution, the incidence of typhoid fever was taken as the most reliable index. Laboratory investigations.-Extensive data have been collected and compiled from bacteriological, chemical, biological, and hydrometric studies covering the whole Ohio River and its main tributaries. All branch laboratories have been discontinued, and all work in connection with investigations of stream pollution conditions is being carried on at the headquarters' laboratory at Cincinnati. The examination of river samples from the Ohio was discontinued June 1, 1917. Since that date the laboratory work has been much curtailed. In June, 1917, samples of both raw and treated water at the Fort Thomas Army post were examined at the request of the military authorities of the post. Examinations were also made of samples of water from private wells and public supplies from Maysville and Calhoun, Ky., to assist the work of survey parties detailed for ruralsanitation studies in these communities. The results of the large numbers of examinations of samples have been carefully studied, compiled, and analyzed for the preparation of a full report. Bacteriological studies. In addition to routine bacteriological examinations, special studies have been made of the preparation of standard media and the perfecting of bacteriological technique with the view of simplifying routine water examinations and establishing a satisfactory basis for interpreting results. Chemical studies. In addition to the routine examinations of water samples for turbidity, alkalinity, oxygen demand, and sanitary and mineral analyses of composite samples, special studies have been carried on in the chemical laboratory. Complete mineral analyses were made of samples of well waters collected in connection with studies of pellagra being carried on by Surg. Goldberger at Spartanburg, S. C. Special research studies. Studies begun during the previous year, by Asst. Surg. Joseph Bolten, on the life of bacteria in stored water samples, were continued and elaborated by Sanitary Engineer H. W. Streeter, in order more definitely to establish the fundamental growth and death rates of bacteria. Special studies were undertaken by Sanitary Engineer Streeter and Sanitary Bacteriologist E. M. Meyer to establish the basic metabolic differences between fecal and grain types of B. coli, as a means of differentiating these two types of organisms. Although this work is left unfinished, satisfactory progress was made in checking up and elaborating upon the previous work of Rogers, Clark, and Lub of the United States Department of Agriculture. The importance of a differentiation between the fecal and nonfecal types of B. coli in the interpretation of the sanitary qualities of water supplies has already received considerable study. A new laboratory medium for the isolation of B. coli was developed by Mr. Meyer and the results published in the Journal of Bacteriology, (Vol. II, No. 3, May, 1917), under the title, "The use of a three per cent lactose litmus agar plate for the demonstration of B. coli in water examinations." An apparently new species of the B. coli group was also isolated by Mr. Meyer from samples of water under routine examinations. This organism culturally resembles members of the B. coli group, but is a spore-forming variety. Plankton studies. Special biological research was begun in October, 1916, by Plankton Expert W. C. Purdy and Sanitary Bacteriologist C. T. Butterfield, upon the food relations existing between bacteria and various animals of the plankton particularly the protozoa, in order to determine whether the activity of certain protozoa constitutes any appreciable factor in the destruction of bacteria. Large numbers of cultures, some of bacteria only and others containing both bacteria and protozoa, were studied over time periods varying from 18 to 200 days. Results indicate (1) that certain protozoa can subsist on a diet of bacteria only; (2) that very large numbers of bacteria are devoured by protozoa; (3) that a definite and direct relationship exists between bacterial content and the native animal plankton of sewage; (4) that physical conditions improve most rapidly in cultures containing both bacteria and plankton. The practical value of these studies lies principally in the demonstrated efficiency of the protozoa in reducing bacteria in sewage or polluted water, thus throwing new light on methods by which natural purification is effected. Laboratory examinations. The following is a summary of the laboratory examinations made during the year. As each sample often requires a series of examinations, the figures given usually represent the numbers of individual samples: Bacteriological examinations: Routine river and tap samples.. 4, 189 4, 056 1,667 471 977 11 2,052 2, 117 |