called Sydneia or Terra Australis. 113 
particles, and, as he considered it to be more pure than the 
former, he subjected it to the fqllowing experiments. 
1. It was digested at three different times with concentrated 
muriatic acid, in a boiling heat, and the acid was afterwards fil- 
trated through paper. The solution was then mixed by degrees 
with pure water, which did not however produce any precipi- 
tate, even when warmed. 
Carbonate of potash caused some flocculi to fall, which, edul- 
corated and dried, weighed 3.25 grains. 
This precipitate was dissolved in diluted sulphuric acid, and 
left a small portion of siliceous earth ; after which the solution, 
by evaporation, afforded crystals of alum. 
2. The residuum of the muriatic solution was mixed with 
three times the weight of potash, and exposed to a red heat. 
Muriatic acid was then poured on the mass, and the insoluble 
gelatinous residuum was edulcorated on a filter; and, after a 
red heat, weighed 19.50 grains, which proved to be siliceous 
earth. 
3. The muriatic solution, with prussiate of potash, afforded a 
blue precipitate ; the ferruginous part of which was about one 
quarter of a grain. 
4. The solution was then saturated with carbonate of pot- 
ash, and some alumine was precipitated; which, after a red 
heat, weighed 8.50 grains, and with sulphuric acid formed 
alum. 
Siliceous earth, alumine, and iron, appeared therefore to be 
the only ingredients of this substance ; but, as Mr. Klaproth 
had no more than thirty grains to examine, he could not extend 
his experiments. 
From those above related, he is of opinion that the existence 
MDCCXC VIII. O 
