852 THE BACTERIOLOGICAL EXAMINATION OF WATER 



new tightly-fitting cork which has been passed through the flame of a spirit 

 lamp until slightly carbonized. Cut off the cork level with the mouth of the 

 bottle and seal with wax or and this is perhaps better cover it with a 

 sterile india-rubber cap. Paste a label on the bottle giving the source of the 

 sample and other particulars. 



The method of filling the bottle will depend upon whether the water is to 

 be taken from a tap, a river, a well, etc. Before taking a sample from a tap 

 the water should be allowed to run to waste for several minutes in order to 

 empty the pipe of any water that may have been standing in it. For a 

 similar reason, in the case of pump water, the water should be pumped to 

 waste for 10-15 minutes before taking the sample. 



In collecting water from a river the bottle should be submerged with the 

 neck pointing up stream : the sample should oot be taken from too near the 

 bank and the stirring up of sediment near the place selected 

 should be carefully avoided. 



When a well is not provided with a pump the bottle may be 

 lowered with string, or filled from a bucket which must be 

 previously well cleansed and then rinsed with the well water. 

 It is however better in such a case to use a Miquel's flask with 

 which water can be collected either from the surface or from 

 any desired depth below the surface. 



Miquel's flask (fig. 407). Miguel's flask is a vessel of special shape the 

 neck of which is drawn out to a length of 5-6 cm. and bent upon itself. 

 Leave the pointed end unsealed and sterilize the flask by heating it 

 strongly in a flame : during the heating the greater part of the contained 

 air vill be driven out and while still hot seal the open end. When cold 

 the llask is weighted with lead fixed to it by means of iron wire and 

 can thus be immersed. A long cord is attached to the apparatus to 

 allow of it being lowered into a well ; and a thin metal wire twisted 

 round and fixed to the narrow pointed end of the flask, long enough for 

 the operator to have one end always in his hand, serves to break the 

 neck. 



To take the sample hold the cord and the metal wire in one hand, 

 lower the flask into the well, and when the apparatus has reached the 

 required depth break the neck of the flask by giving a sharp pull on the 

 iron wire. The flask rapidly fills with water and as soon as it is filled 

 raise it and seal the open end in a spirit flame. 



Other apparatus. Miquel's apparatus will usually be found adequate 

 but there are many other pieces of apparatus designed for the same 

 purpose and from among these Guillemin's and de Foa's, which are 

 constructed in such a way as to ensure the automatic closing of the 

 flask as soon as it is filled, may be mentioned. 



Transmission. Organisms will rapidly multiply in water at the ordinary 

 temperature of the atmosphere so that it is necessary in the case of water 

 intended for bacteriological examination that the sample should be kept at 

 a temperature of about C.~ a temperature which will inhibit multiplica- 

 tion from the moment of collection until the examination is commenced. 



When the water has to be sent some distance the following method of packing 

 may be adopted. 



Place the bottle containing the water in a metal box just large enough to hold it 

 tightly, and for greater safety the lid may be secured with an india-rubber band over 

 the joint. Place this box in another larger metal box a biscuit box does very 

 well and fill the latter with ice ; then place the second metal box in a larger wooden 

 box, filling the space between the two with sawdust rather loosely packed. This 

 arrangement will keep the sample of water at the temperature of melting ice for 

 24-72 hours depending upon the time of year and the amount of ice used. The 

 water should invariably be sent to the laboratory by the most rapid means of 

 transit. 



The second metal box may be dispensed with and in this case the metal case into which 



FIG. 407. 

 Miquel's appa- 

 ratus for the 

 collection of 

 water at differ- 

 ent depths. 



