COLLECTION OF THE WATER 853 



the bottle fits tightly is packed round with ice and sawdust a large quantity of the 

 latter will of course be necessary to absorb the water from the ice as it melts. 



[Houston has devised a very convenient piece of apparatus for the collection 

 and transit of water for bacteriological examination. 



[It consists of a rectangular wooden box with an hinged lid the whole lined with 

 thick felt. The box contains an hollow water-tight copper vessel which fits two sides 

 of the wooden box closely destined for the reception of ice and closed above with 

 a large india-rubber bung. The remainder of the space is occupied by a felt box 

 open above and divided into compartments for the reception of flat rectangular 

 bottles. The wooden box with its felt lining acts as a non-conductor of heat and the 

 copper vessel with its contained ice keeps the temperature at as near C. as possible. 

 The bottles used are ground-glass-stoppered bottles of 8 ozs. capacity. The stopper 

 should be covered with paper before sterilization and this should not be removed 

 until the water is to be collected. ] 



Particulars to accompany the sample. Full particulars as to the source 

 of the water, the nature of the examination required, etc. should accompany 

 the sample so that as much information as possible may be furnished upon 

 which to base an opinion. 



The following is a copy of the official form in use in the French military sanitary 

 service : 



Particulars of the water sent for examination by 



(1) Authority by whom sent 



(2) Reasons for sending (epidemic, spring to be tapped potable water, etc.). 



(3) Source of the water (spring, well, filtering gallery, cistern, reservoir, etc.). 

 State the depth of the well, cistern, or reservoir and the level of the water at the 

 time of collection. 



(4) Exact place where the water was collected (e.g. whether from the spring 

 itself or from a tap at the end of a conduit whether from a well or from a pump 

 connected with the well) : never collect the water which first issues from a tap or 

 a pump. If the water is taken from a river, well or reservoir, state whether collected 

 from the surface, or from the bottom or from some intermediate point. State the 

 last occasion on which the cistern or reservoir was cleaned and whether there is dust 

 on the surface or sediment at the bottom. 



(5) Has any rain fallen or snow melted in the few days preceding the taking of 

 the sample ? Is the water muddy ? Is the level above or below normal ? 



(6) State any cause of permanent or accidental pollution to which the water 

 appears to be exposed. 



(7) The purposes for which the water is required (i.e. for drinking purposes, 

 cooking, lavatories, watering horses, etc.). 



(8) Is the water used for drinking without previous purification ? State, if there 

 is any, the apparatus used for purification. 



(9) Atmospheric temperature at the time of collection. 



(10) The temperature of the water at the same time. 



(11) Day and hour of collection. 



(12) Other remarks. 



SECTION II. METHODS OF EXAMINATION. 

 1. Enumeration of the organisms. 



Numerous methods of enumerating the organisms in water have been 

 suggested. Some bacteriologists base their methods upon isolation by 

 dilution in liquid media (p. 76) (Miquel). Others adopt the method of 

 isolation on gelatin plates (Koch). 



It is not proposed to discuss the pros and cons of these different procedures 

 but those in most general use will now be described in detail. 



General rules. The cubic centimetre is generally adopted as the unit of 

 volume in enumerating the number of organisms in water and it is customary 

 to speak of a water as containing say 50,000 organisms per c.c. 



