204 Intelligence and Miscellanies. 
“The other a age 5 is called Stipsy by the inhab- 
itants. It is near the e of the island, and was well 
known to the ancients, beige spoken of by Pliny, as afford- 
ing an alum, held next in estimation to that procured from 
Egypt. This is a cave sacle and at the bottom ofa hill. I 
entrance is low and narrow, but it forms a chamber one hun- 
dred and twenty feet in length. Its atmosphere preserves a 
heat of 90°, and in some — of 100° Fah. The rock 
forming the roof and sides is of a = consistence, and 
every where inflated into sara coalle 0 
It is in these cells that we find the alum, which lines them 
all around with the most riracire a. or frost work. 
Towards the entrance of the cave occur masses of branchy 
gypsum, and within delicate acicular seyals of the same 
substance.” 
As soon as I saw the Milo alum, I was struck with its 
was immediately led to think of the native soda ay of 
South America, recently analyzed and made known by Dr. 
Thomson.* T accordingly made use of the following pro- 
= to render my conjecture concerning its nature, certain. 
A portion of it was dissolved in water, to which was ad- 
ded in excess, carbonate of ammonia, to precipitate the alu- 
mine and other earths, as well as any metallic oxides which 
might be present. The residual liquid was evaporated to 
dryness and heated to redness in a platina crucible to dissi- 
pate the ammoniacal salts. The residue was dissolved in 
water, in which it proved highly soluble. By its taste it was 
pan to sulphate o — — BPs solution was set 
aside for spontaneous lr n. It shot into short pris- 
matic crystals, which o aaa ‘tightly heated underwent 
the watery fast: n the course of a few days, the entire 
mass became covered with a white efflorescence. There- 
fore, there can remain no reasonable doubt concerning the 
nature of the substance in question 
he specimen examined was from the: cave first mention- 
ed, between which and the specimens from the other, there 
is a slight difference in appearance ; they are both however 
the same in all important respects. The former consists of 
_ parallel straight fibres not very closely aggregated, from one 
* Annals of the Lyceum of Natural History of New York, Vol. III, p. 19. 
