586 MICROSCOPICAL EXAMINATION OF WATER. 
lime in the charcoal is dissolved out by the water when passing 
through it. 
I have made some special experiments with phosphates in 
pure distilled water, under various conditions, and the results 
showed that in every case when phosphate of lime was present, 
the liquid, on the addition of cane-sugar thereto, became 
turbid and literally alive with bacteria, in times varying from 
twelve to thirty hours. The phosphates of the alkalies gave 
negative results, but when nitrate of ammonia was present, a 
slight turbidity occurred after the lapse of several days, and 
the liquid was found to contain a few bacteria. The results 
of these experiments confirmed my previous observations, 
that the phosphate of lime possessed powerfully stimulating 
properties in promoting the development of organisms. The 
phosphates of the alkalies, however, in the presence of pure 
vegetable albumen, also promote the development of 
organisms, and produce turbidity in cane-sugar solutions. 
I also made various experiments with water passed through 
animal charcoal, and with water to which animal charcoal had 
been added, and in every instance when sugar was added, and 
the mixture placed in a chamber maintained at a temperature 
between 60° and 70° Fahr., the sample became turbid, in times 
varying from twelve to forty hours. 
I have since observed that animal charcoal which has been 
in use for a considerable length of time ceases to possess the 
property of imparting to the water the power of producing 
turbidity on the addition of sugar; doubtless from all the 
phosphate of lime having been dissolved out by the long and 
constant action of the water. 
Hitherto in the course of my experiments both with phos- 
phates and urine I failed to obtain any characteristic 
mycelium ; but it occurred to me that so long as the field 
was occupied by such a mass of bacterian bodies, there was 
but a small chance of obtaining the development of any other 
organisms, and as I had observed that the greater the pro- 
portion of urine or phosphate of lime present in the water, 
the water not only became turbid within a shorter time, but 
the bacterian bodies were greatly increased in number. 
To obviate this I experimented with more dilute solutions. 
I first made an experiment with one drop of fresh urine in 
20 ounces of New River water, and the result was completely 
successful, and I obtained an exquisitely beautiful filamentous 
development corresponding to the characteristic mycelium 
described. 
Now, I had observed that the bacterian bodies produced in 
New River water, when a phosphate was present, were 
