Royal Microscopical Society. 165 



tions, that the phosj^hate of Hme possessed powerfully stimulating 

 properties in promoting the development of organisms. The phos- 

 phates 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 mix- 

 ture 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 pro- 

 perty 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 obtain- 

 ing the development of any other organisms, and as I had observed 

 that the greater the proportion of urine or phosphate of lime pre- 

 sent 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 Eiver water, and the result was completely successful, and 

 I obtained an exquisitely beautiful filamentous development corre- 

 sponding to the characteristic mycelium described. 



Now I had observed that the bacterian bodies produced in New 

 Eiver water, when a phosphate was present, were identical in appear- 

 ance and character with those which were produced by the addition 

 of fresh urine to a portion of the same water, and it was difficult 

 to comprehend how, when fresh urine was used, one class of the 

 organisms developed corresponded with those produced in the pre- 

 sence of phosphate ©f lime, while the filament was absent. 



To try and assimilate more the conditions of making the experi- 

 ments with a phosphate and the urine, I added very minute 

 quantities of phosphate of potash to New Eiver water — from two 

 to five hundredths of a grain to 40 ounces — and with this pro- 

 portion of phosphate a beautiful filamentous development similar to 

 that which was produced by the one drop of urine, made its ap- 

 pearance, thus clearly indicating that phosphate of lime exercised an 

 important part in causing the development. 



N 2 



