ON AMERICAN BROMINE, 
95 
2 Mg 0, P0 3 + 2 HO + 10 HO,) and deducting the amount of 
this sait from the rest, (omitting the insoluble matter and 
hygroscopic moisture), it will be seen that the concretion 
is composed mainly of the phosphate of magnesia and 
water, according to the following formula, 3 MgO + 3 HO-h 
2 PO -f 21 Aq. as will be seen from the following compo- 
sition : 
By Experiment. By Calculation- 
Phosphoric acid, 33.56 2 P0 5 , . . . 33.70 
Magnesia, . . 14.55 3 MgO, . . . 15.20 
Water, . . . 51.89 24 Aq. . . . 51.00 
100.00 100.00 
ART. XXI ON AMERICAN BROMINE. 
By George W. Patrick. 
(Extract from an Inaugural Essay.) 
This interesting substance, within the last two years, has 
been found very abundantly in the bittern or mother liquor, 
remaining after the crystallization of salt from the evapo- 
rated waters of the Salt Springs, near Pittsburg, Pennsyl- 
vania ; and from the facility with which it is now extracted? 
will undoubtedly prove a source of considerable revenue to 
those engaged in obtaining it. 
Edward Gillespie, M. D. ? while a student, first discovered 
this substance in these waters by testing them for iodine. 
These waters yield about 1.13 per cent, of bromine, being 
nearly equal to the celebrated springs of Germany. The 
gentlemen now engaged in obtaining it have patented their 
process, which is said to be so simple and economical as to 
