292 
THE PRINCIPLES OF BOTANY. 
sinks were observed, and at once ordered to be remedied 
The well water was found to be deficient, and when near the 
bottom became turbid; when in plenty it was clear and 
bright. Its taste was not objectionable, and chemical tests 
gave no indication of deleterious principles, except that 
organic matter prevailed; but on subjecting some of the 
water to microscopic examination the “ sewage fungus” was 
at once apparent, and the facts revealed by this instrument 
fully justified the following observations of Dr. Lankester : 
“ Not one of the least important services rendered by the 
microscope is the facility with which the presence of organic 
matters, especially when living, can be detected by its agency 
in positions where chemical analysis fails to recognise such 
compounds at all. This is remarkably the case with the lower 
forms of animal and vegetable life, which inhabit fresh, mine- 
ral, and marine waters. Some of these animals, as, for in- 
stance, the jelly fishes, which are large enough to be seen by 
the naked eye, and even to present creatures of formidable 
dimensions, are scarcely recognisable by chemical analysis in 
the waters in which they have existed. Such facts as these 
seem to indicate that the microscope may be successfully 
employed in investigating waters which may be suspected of 
containing deleterious matters, or of determining the presence 
of agents injurious to health. It is true that our knowledge 
of the forms of microscopic life which may be injurious to 
health is very limited, but sufficient is known to stimulate 
further inquiry, and to prompt further efforts to identify 
special organic forms with the unfitness of water for dietetical 
purposes.” 
It was just this conclusion, which we had arrived at some 
years since, that induced us to examine the union well more 
minutely, and, having first ascertained the presence of organic 
matter in the water, to ascertain whence it came, and it was 
soon found that, as it oozed in down the sides of the well, it 
could only come from percolating from drains and cesspools, 
here, too, made less deep than the wells in a porous stratum. 
This, on being put right and all sources of contamination ex- 
cluded and the well deepened, was speedily followed by a 
clean bill of health, in as far as fever was concerned. 
Our own family all succumbed to fever in one of the 
healthiest spots in the country, when our medical attendant 
was at once down upon the water ; and here, too, the micro- 
scope demonstrated the sewage fungus. This in a well 125 
feet deep was difficult to account for, but it was subsequently 
ascertained that a drain was made to run near the top of the 
well ; it leaked, and it is satisfactory to note that, this fault 
