264 REPORTS FROM THE SECTIONS. 
Notes on the Incrustation of the Sydney Water-main. 
By Dr. Morris. 
[Read before the Microscopical Section, 12 August, 1878.] 
Axout six weeks ago, one of the water-mains which supply this 
city with water burst, and having seen a notice in the papers that 
the inside of the pipe was encrusted an inch thick with a soft sub- 
stance, I at once obtained a sample, but instead of being soft, I 
found ‘that it consisted of layers of oxide of iron, with other ingre- 
dients. This deposit I now submit for your inspection. On boil- 
ing a portion of this deposit we muriatic acid, and afterwards in 
nitric acid, washing, and collecting the sediment, a microscopical 
examination of it proved rc it contains a substance not accounted 
for in the following analysis, which was forwarded to the Mayor 
of Sydney by Mr. Charles Watt, and published in the Sydney 
orning Herald of July 17th :-— 
- Sir, —I have the honor to acknowledge the receipt of your communication 
. the 9th inst., and the packet containing as substance which had been found 
he 
this incrustration consists chiefly of oxides of iron, a large proportion of 
i¢ Oxi i i Wensatited action 
A microscopical exniiteation did not show the ee of any forms of _ 
live animalcule. I have the honor, 
CHA ARLES WATT. 
Analysis of substance forming an sacgewr yn on the inner surface of cer- 
tain water mains.— PP operon seni dried at 300° Fahrenheit before analysis. 
Oxides of iron (magnetic peroxide), 793; * ila (chiefly in the form of sand), 
45; volatile at red heat (consisting of combined water and organic matter, 
15°1; alumina, races of chloride of sodium, lime, loss, &c., 6°100°0 
I now submit AG your examination a slide prepared from the 
sediment after treatment as above. “This preparation consists of 
minute spheroidal bodies partly adhering to one another, accom- 
ied by the silicious spicule which ‘I once exhibited to you 
