Rowley- rag-Hone and the Toad-Hone. 
335 
was 7 , -o* R could not be fufed by the greater heat of a blow- 
pipe, but melted into a glafs when mixed with calcareous 
earth. 
I. The undiflolved part (exp. C.) was not fufible by itfelf ; 
nor was it atled on by vitriolic, nitrous, or marine acid. It 
melted into a glafs with foffil alkaly. 
K. The precipitate of 7_ s _ (exp. F.) after a fufficient expo- 
fure to heat was put into an ounce of water : the next morning 
the water had a pellicle upon its furface, and tailed like lime- 
water. 
Hence it appears, that ico parts of this fpecimen of Toad- 
Hone contained 
From the addition of i T l 0 - of weight it is probable, that the 
fubHances capable of uniting with fixable air were not in the 
fpecimen ufed fully faturated with -it, as they w r ould be after 
Upon repeating thefe experiments with different portions of 
the Toad-Hone, the quantities of the calcareous earth were 
found to differ a little ; but nothing further appeared to invali- 
date the general conclufions. 
CONCLUSIONS. 
C. Siliceous earth . 
H. More ditto 
D. Calciform iron 
F. K. Calcareous earth 
G. H. Earth of allum 
ioi * 
their precipitation by the mild alkaly. 
A Table. 
