PHYSICAL and LITERARY. 343 
_ gathered, and were fufpended, in the mid- 
dle of the water; and a great number of 
{mall air-bubbles, like particles of quick-fil- 
‘ver, appeared adhering to the bottom of the 
glafs, to its fides, and upon the furface of 
the water; multitudes of the like air-bubbles 
were intermixed with the green clouds: after 
ftanding about an hour, a great many of the 
air-bubbles difappeared, and the clouds in the 
middle of the water grew thicker, and of a 
darker green, and afterwards precipitated. 
| 11. AN aqueous folution of faccharum Sa- 
 turni, turned it a little whitifb, but not fo 
- much as it did the river-water; and much 
def then it did the river-water, when there 
 wasa very little fea falt diffolved in it; in all 
 thefe three trials, a white powder precipita- 
ted. 
12. On September ft, 1 poured a chopin or 
_ _Englifh quart of this water into a clean, white 
- ftone-bow!; and coyered it witha plana of 
"paper, to keep out the duft. 
Ow the ad, there was precipitated a brown 
_ powder, like brick-duft ; and, on the furface 
ofthe water, there were many fhining fpan- 
(gles of a copper-like colour. 
On 
