. Bacteriology and the public health. Bacteriology; Public health. 464 APPENDIX the same principle applies to a well not in regular use. Such a well should be pumped for some time before taking the sample. For obtain- ing samples from a considerable depth Miquel's apparatus may be used, or, if that is not available, a weighted bottle. After collection, the bottle should be at once stoppered, labelled, and packed in ice and sawdust for transport to the laboratory, or placed in one of the various ice cases now in use (Delepine's or Pakes'). Below 5° C, organisms do not multiply in water, and the
. Bacteriology and the public health. Bacteriology; Public health. 464 APPENDIX the same principle applies to a well not in regular use. Such a well should be pumped for some time before taking the sample. For obtain- ing samples from a considerable depth Miquel's apparatus may be used, or, if that is not available, a weighted bottle. After collection, the bottle should be at once stoppered, labelled, and packed in ice and sawdust for transport to the laboratory, or placed in one of the various ice cases now in use (Delepine's or Pakes'). Below 5° C, organisms do not multiply in water, and therefore it is important to keep samples previous to examination at a low temperature. In all cases where it is possible, the water should be examined at once after collection. Physical Examination.—The temperature and reaction of the water should first be tested, and an examination made of any deposit or suspended matter. Bubbles of gas, if present, should be noted. The colour, character, and amount of particulate matter in suspension or sediment should be observed and noted ; turbidity, odour, flavour and taste, peatiness, etc., should all be noted. A record of the quantity of the sample, its source, and the date and time of its collection is also important. A microscopical examination of the matter obtained by filtration followed by centrifugalisation may also yield important facts. Bacteriological Examination.—This divides itself naturally into two divisions—(«) a quantitative examination, and (6) a qualitative examina- tion.* (a) Quantitative Examination The sample should be gently mixed, and plate cultivations made. Take five tubes of 10-15 of gelatine and five Petri dishes, and melt the medium of the former in a water bath. The gelatine should be well liquefied, but not overheated. The Petri dishes should be of even surface, equal size, and properly sterilised. Take a 1 sterilised. Please note that these images are extracted from scanned page images that
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