TABLE VII.-Number of children included in the study, total possible number of days of school attendance, and days absent on account of sickness and of causes other than sickness, by months, for the school year 1919–20, in certain localities in Missouri, Age and sex. Total school 1919. 1920. year. Sept. Oct. Nov. Dec. Jan. Feb. Mar. Apr. May. Number of children... Total possible days of 325, 150 26,640 27,640 28, 260 28,940 33,000 35,580 50, 601 52,633 41, 856 1,138 1,396 2,000 4,228 3,333 3,029 1,345 10,555 769 744 1,066 1,111 1,575 1,411 1,443 1,764 1,649 1,294 1,473 1,690 1,829 344,064 27,380 28,220 28,860 29,460 33, 700 36, 580 Days absent-Sickness. 19, 926 391 755 1,284 1,823 2,226 4,163 180, 702 14,580 15, 120 15, 460 15, 780 18, 460 19,540 29,668 28,944 23, 150 Days absent-Sickness. 13, 061 Days causes.... 11 to 18 years: 209 4,778 320 500 897 1,196 770 702 537 2,957 1,280 1,317 1,340 1,378 1,532 1,685 2,547 2,673 2, 148 317,901 25,600 26,340 26,800 27,560 30,540 33, 700 51,521 53, 773 42,067 Days absent-Sickness. 12, 955 1,868 1,754 1,171 765 833 1,190 1,249 1,024 Days absent--Sickness. school attendance.... 154, 539 12,800 13, 240 13, 400 13, 880 15, 300′ 16,660 24,025 25,081 20, 153 Days absent - Other causes.. Girls Number of children. Total possible days of 767 $52 1,357 1,424 1,124 Days absent-Sickness. Days absent — Other school attendance.. 163,362 12, 800 13, 100 13; 400 13, 680 15, 240 17,040 27, 496 28,692 21,914 357 627 S05 1,465 1,399 1,177 causes.. 255 567 TABLE VIII.-Number of days lost from school on account of sickness of known cause and number of cases of known diseases among school children 6 to 18 years of age, in certain localities in Missouri during 1919–20.1 Disease. Days lost: All known dis Total school year. Septem- Octo- Novem-Decem- Janu- Feb- March. April. May. ber. ber. ber. ber. ary. ruary. 95 Influenza... 2,541 Cases: All known dis eases.. All known dis eases (exclu sive of influ enza)... Influenza.. 1 Data given here are for only the small part of the total absence from sickness in which the specific disease was reported. TABLE IX.-Number of days lost from school on account of sickness of known cause and number of cases of each known disease causing absence among children 6 to 18 years of age, in certain localities in Missouri during 1919-20.1 Data given here are for only the small part of the total absence from sickness in which the specific disease was reported. DISINFECTANT TESTING BY THE HYGIENIC LABORATORY METHOD. The following method for determining the phenol coefficient of disinfectants supersedes the methods described in previous publications of the Public Health Service and is the present Hygienic Laboratory method. No single method can serve as a means of comparing the value in practice of disinfectants of greatly diverse composition and destined for a variety of applications. However, disinfectants which are chemically related to phenol, which are to be used against organisms reacting similarly to the manner in which the typhoid bacillus reacts and which are destructive within the time and temperature limits of this test, may be compared as to their disinfecting properties within these limitations by means of this test. The results may be useful in the selection of a potent product, in making comparisons of cost in terms of service rendered, and in checking successive batches of the same product. This method was submitted to several different laboratories for trial before its adoption, and the results seem to justify the belief that the personal equation in the performance of the tests does not play an inordinate rôle. THE TEST CULTURE. The test culture is a culture of Bacillus typhosus, Hopkins strain. Between periods of testing it is maintained on nutrient agar stabs, transferred at monthly intervals. For at least 5 days before the test the culture is transferred at 24-hour intervals to successive tubes of the meat extract broth described below and incubated at 37° C. Transfers are made with one standard loopful. The culture is filtered through sterile filter paper just before using. The test is performed with a 24-hour culture. THE PHENOL. The phenol must comply with the requirements of the Eighth United States Pharmacopoeia. Particularly the congealing point must not be below 40° C. The crystals are kept in tightly stoppered amber-colored bottles in a dark and relatively cool place. A 5 per cent original solution is made by adding 1 part by weight of phenol, liquefied by warming the bottle, to 19 parts of distilled water. A fresh solution is made for each day's use. THE CULTURE MEDIUM. Make meat extract medium as follows: Beef extract (Liebig's). Peptone (Armour's for disinfectant testing). Sodium chloride.. Water, distilled.. Boil for 15 minutes. 3 gm. 10 gm. 5 gm. 1,000 c. c. Make up to original weight by addition of water. Filter through paper. Tube, 10 c. c. to each tube. Sterilize. The pa value of this medium should be between 6.0 and PH GLASSWARE AND APPARATUS, Glassware for measuring must be accurately graduated. It must be clean, dry, and sterile at the time of use. There will be needed 100 c. c. measuring cylinders, graduated in 1 c. c., glass stoppered. Seeding tubes, 1 x 3 inches, flared tops, round bottoms. Racks consisting of blocks of wood with rows of holes for both the seeding tubes (before they are placed in the water bath) and the subculture tubes. Wire loops must be carefully made and kept from damage. They are made as follows: A close cylindrical spiral is made by winding a piece of platinum wire, No. 23, B. & S. gauge, as tightly as possible about a piece of steel or other hard wire having a diameter of 0.072 inch (No. 13, B. & S. gauge) to complete a little more than four full turns. The long end of the wire is then bent sharply at right angles to the wound portion and parallel to the steel wire. The core is removed and the short end of the wire is clipped off so as to leave exactly four full turns to the coil. The successive turns of the spiral must touch one another continuously. The long end of the wire is attached to an aluminum handle. A convenient support is provided on which to rest the loops so that a batwing Bunsen burner may be placed under each one successively. A constant temperature bath is provided, capable of maintaining the seeding tubes at 20° C. during the time of the test. A wellinsulated bath of large volume relative to the surface exposed is sufficient without thermoregulating appliances. Disinfectant testing machine. The use of a disinfectant testing machine is optional. One is described in Reprint No. 462 from the Public Health Reports. A few modifications have proved useful. For example, the use of platinum instead of nichrome loops, and the practice of sterilizing the subculture tubes covered with padded inverted troughs in the racks. DILUTIONS. Dilutions of phenol and of disinfectants are made from the original liquid on the day of the test. For the dilutions of the disinfectant, a 5 per cent solution is made by adding 5 c. c. of the disinfectant to 95 c. c. of sterile distilled water. A standardized 5 c. c. capacity pipette is used for this purpose. After filling the pipette, all excess of the disinfectant on the outside of the pipette is wiped off with sterile gauze. For the higher dilutions, delivery pipettes may be used. The fol- For dilutions up to 1:70, increase or decrease by a difference of 5 necessary. It is important that the cylinders used for making the dilutions be |