APPENDIX 487 



plates, it will, of course, be necessary to multiply up according to degree 

 of dilution of the pallial liquor with sterile water in making the emulsion 

 in the first instance.* 



Examination Of Urine. Urine is examined in the same way as 

 water or sewage effluent. Plates (gelatine and agar) and sub-cultures 

 are made in the usual way. The urine should also be centrifugalised 

 and the sediment carefully examined by microscope and culture, and if 

 necessary inoculated into guinea-pigs. The organisms chiefly to be 

 looked for are B. typhosus (in cases of typhoid fever), B. tuberculosis, 

 septic organisms, and B. coli. 



Examination Of Ice-cream. Ice-cream usually contains vast 

 numbers of bacteria. It is examined in the same way as milk, and 

 requires high dilution before examination. 



Examination Of Meat, Fish, etc. Mince a portion of the unsound 

 meat or potted meat or fish by aid of sterile scissors and forceps, and 

 make an emulsion in broth in a flask at 42 C. (for thirty minutes). 

 Shake. Pipette off 10 c.c. of extract for inoculation of animals. Make 

 plates and further tube cultures of the emulsion. Incubate duplicates 

 anaerobically in Bulloch's apparatus. Feed animals on portions of the 

 samples. 



Methods of Examination of Sewage and Sewage Effluents 



The sample of sewage or effluent to be examined must be collected 

 in the same manner as in water. 



1. Physical Examination. Take note of quantity, colour, character 

 and amount of deposit and suspended matter, reaction, temperature, 

 bubbles of gas, etc. 



2. Dilution. This must be carried out as in the examination of milk, 

 500-1000 times. 



3. Quantitative Examination. Make plates on Petri dishes, gelatine 

 for incubation at 20 C., and agar at 37 C. Sewage is rich in intestinal 

 germs, most of which grow luxuriantly at blood-heat. 



4. Qualitative Examination. The three chief organisms of sewage 

 are : (a) B. coli (p. 46), (6) B. enteritidis sporogenes (pp. 156 and 307), and 

 (c) sewage streptococcus (p. 155). It is necessary, therefore, to examine 

 particularly for these organisms. It may also be necessary to estimate 

 quantitatively for B. coli and B. enteritidis sporogenes.^ 



5. Subsidiary Differential Tests. Inoculation of animals test ; produc- 

 tion of gas in gelatine " shake " cultures in twenty-four hours at 20 C. ; 

 acid clotting of litmus milk in twenty-four hours at 37 C. ; greenish- 

 yellow fluorescence in neutral-red broth cultures in twenty-four hours 

 at 37 C. ; the production of indol within five days at 37 C. ; and the 

 bile-salt broth test (growth, gas, and acid). 



* A large number of methods and modes of experiment in the investigation of 

 Oysters will be found in the appendices of the Fourth Report of Royal Commission 

 on Sewage Disposal, 1904, vol. iii., pp. 191-309 (Houston). 



t For methods, see Royal Commission on Sewage, Second Report, 1902, p. 140 

 (Houston). 



