The Use of the Microscope in the Brewing Industry. 263 
which both chemical and biological tests and investigations are 
daily carried out, and much of the time of the scientific staff has 
to be devoted to examinations of the yeast, to the forcing of beers 
as a test of stability, to the testing of the efficiency of the air-filters, 
and to the investigation of difficulties when such arise. In the 
case of breweries where there is not a resident scientific staff, 
arrangements are almost invariably made for the work to be done 
by some independent consultant. It will be seen, therefore, that 
the microscope is to the modern brewer what the compass is to 
the navigator. It is an instrument to which recourse is constantly 
being had, and without its aid the brewer, like the navigator 
without a compass, would speedily find himself on the rocks. 
