20 Canadian Record of Science. 
the number of bacteria at the surface of the water. In the 
case of a rapidly flowing stream this is of little moment as 
the water is sure to be thoroughly mixed and the bacteria 
pretty evenly distributed. In standing bodies of water, 
such as lakes, ponds, reservoirs and wells, the bacteria for 
the most part sink to the bottom, so that the number of 
bacteria found at the surface affords no indication of their 
number in the deeper part, from which usually supply pipes 
are fed in the case of drinking waters. 
In the course of a recent biological examination of the 
waters of the Ottawa and St. Lawrence rivers it was 
found necessary to take samples at some distance beneath 
the surface. In winter, when samples were obtained 
through a hole cut in ice, often from one to two feet 
in thickness, the water which welled up into the hole 
was found to be contaminated by the instruments used 
in cutting it. On one occasion the water in the ice hole 
yielded 8,000 colonies per c.cm., while a sample obtained 
from the running stream beneath the ice only gave 30. 
Lying beneath the solid ice running water there is 
often found a stratum of “ frazil” ice. This consists of a 
dense mass of small, sharp ice fragments which have at one 
time been in contact with the bed of the stream and have 
then become contaminated fiom the soil. That water 
obtained from the midst of a bed of “‘frazil” ice is unsuit- 
able for bacteriological examination was shown by one 
examination of St. Lawrence water made in mid-winter, 
when two samples from a bed of frazil yielded respectively . 
473 and 480 colonies per c. cm., while clear water from an 
adjacent spot gave only 77 and 39. 
In endeavoring to obtain some apparatus suitable for 
obtaining deeper samples, I was surprised to find no men- 
tion of anything of the kind in any dealers’ catalogues ; 
their poverty in this particular contrasting strangely with 
the wealth of appliances available for other purposes. 
It thus became necessary to procure some simple form of 
apparatus, secure from sources of extraneous contamination 
