SOME NEW SULFONPHTHALEIN INDICATORS. A Preliminary Note. By BARNETT COHEN, Associate Chemist, Hygienic Laboratory, United States Public Health Service. For the determination of H-ion concentration by the colorimetric method, the indicator series of Clark and Lubs has been found extremely useful. Improvement of this indicator series may be sought in two ways: One is the introduction of suitable indicators to fill gaps in the pH scale not now adequately covered; the second is in the substitution of a sulfonphthalein compound for methyl red. As is well known, methyl red is much less stable than the sulfonphthalein indicators and is readily reduced. Clark and Lubs retained it in their series because methyl red was at that time indispensable in covering an important pH range. The following new sulfonphthalein indicators are suggested as filling the above requirements. The dyes were synthesized in the usual way, complete details of which will be published later. Brom cresol green covers almost perfectly the range of methyl red, the apparent dissociation constants in terms of pH being 5.00 and 4.95, respectively. Brom phenol red and chlor phenol red, because of their color changes (yellow to red), may be used advantageously where the dichromatism of brom cresol purple is a disturbing factor. The protein and salt errors of these new indicators remain to be determined. It is tentatively assumed that such errors are of the same magnitude as those of the other sulfonphthaleins now in use. INFLUENZA IN THE UNITED STATES. The following table shows the numbers of cases of influenza reported by State health officers, by telegraph, for the week ended January 27, 1923, compared with similar reports for the corresponding week of 1922, 1921, and 1920. Similar tables covering the period from October 1, 1922, to January 20, 1923, were published in the Public Health Reports December 29, 1922, page 3204; January 12, 1923, page 64; and January 26, 1923, page 141. Cases of influenza reported by telegraph by State health officers for the week ended Jan. 27, 1923, compared with similar reports for the corresponding week of the years 1922, 1921, and 1920. The following table shows the numbers of deaths from pneumonia (all forms) and influenza, combined, in certain large cities of the United States for the weeks ended January 13 and 20, 1923, as reported by city health officers. A similar table covering the period from December 3, 1922, to January 6, 1923, was published in the Public Health Reports January 19, 1923, page 101. 3 2 (1) eeee 763 32 2 (1) 33 30 176 48 3878 (1) 37 260 902 (1) 37 6,615 Deaths from pneumonia (all forms) and influenza, combined, in large cities of the United States, January 7 to January 20, 1923, inclusive. TYPHOID FEVER, MINNESOTA, 1921.--CORRECTION. In the table on page 3206 of Public Health Reports for December 29, 1922, the number of deaths from typhoid fever in Minnesota during 1921 was given as 888. This number should have been 88. The rate given, 3.6 per 100,000 population, was computed on the basis of 88 deaths. Examination for Entrance into the Regular Corps of the Public Health Service. Examinations of candidates for entrance into the Regular Corps of the United States Public Health Service will be held at the following-named places on the dates specified: Chicago, Ill., March 12, 1923. San Francisco, Calif., March 12, 1923. Candidates must be not less than 23 nor more than 32 years of age, and they must have been graduated in medicine at some reputable medical college, and have had one year's hospital experience or two years' professional practice. They must pass satisfactory physical, academic, and professional examinations before boards of commissioned medical officers. Successful candidates will be recommended for appointment by the President, with the advice and consent of the Senate. Requests for information or permission to take this examination should be addressed to the Surgeon General, United States Public Health Service, Washington, D. C. DEATHS DURING WEEK ENDED JANUARY 20, 1923. Summary of information received by telegraph from industrial insurance companies for week ended January 20, 1923, and corresponding week of 1922. (From the Weekly Health Index, January 23, 1923, issued by the Bureau of the Census, Department of Commerce.) 11.2 9,481 10.3 Death claims per 1,000 policies in force, annual rate.... Deaths from all causes in certain large cities of the United States during the week ended January 20, 1923, infant mortality, annual death rate, and comparison with corresponding week of 1922. ( (From the Weekly Health Index, January 23, 1923, issued by the Bureau of the Census, Department of Commerce.) Annual rate per 1,000 population. Deaths under 1 year per 1,000 births-an annual rate based on deaths under 1 year for the week and estimated births for 1922. Cities left blank are not in the registration area for births. Deaths from all causes in certain large cities of the United States during the week ended January 20, 1923, infant mortality, annual death rate, and comparison with corresponding week of 1922. (From the Weekly Health Inder, January 23, 1923, issued by the Bureau of the Census, Department of Commerce.)-Continued. |