Eruption of Mauna Loa in 1851. 395 
lybdate of ammonia, this, as well as the nitric acid, should be in 
decided excess. ‘I'o ascertain when this is the case, before filter- 
ing off the solution, a drop of it may be taken up with a pipette 
and transferred to a test tube containing solution of sulphuretted 
hydrogen, when the brown precipitate ‘of sulphuret of molybde- 
hum will appear. 
After separating the precipitate from the solution, the latter 
should always be allowed to stand for some time in a warm place 
to see whether any additional precipitate is formed. 
TRIALS. 
I. Taken 0: 1199 gramme of tribasic phosphate of soda, which 
was dissolved in nitric acid, a pure solution of lime added, and 
the — ic ‘acid determined according to the directions 
already giv 
Coleutated, Found, 
bid : 00238 - : 00243 
Il. Taken 0: 069 gr. of phosphate of soda and mixed with solu- 
tions of iron, alumina, lime, iegeoue and potash; the phos- 
phoric acid then determined as befor 
cl Found, 
37 00146 
- . é 
Ill. Taken 0-0463 « or. of pointe of soda, mixed with solu- 
tions of the same substances as in the last, and the phosphoric 
acid determined i in the same manner. 
aan. Found. 
p 
These results easeviesh those of Sénbaukheln, and show that 
the method, as regards accuracy, is all that can be desired, while, 
in point of simplicity, it is superior to any of the old processes. 
It will prove of especial advantage in cases, where, as in the 
analysis of svils, a small quantity of phosphoric acid is associated 
with a variety of other substances existing in much larger pro- 
rtion. 
‘New Haven, March 1852. 
Arr. XXXVIIL <0" the jraje poset of Mauna Loa in 1861; 
from a letter to Mev. C. S. Lyman, by Rev. T. Coan, dated 
Hilo, Hawaii, Oct. Ist, 1851. 
I Have wasted several days hoping to get more definite and 
reliable information pesbectug.8 a recent voleanie eruption. Some 
facts are before me and these allow me oe es nunic ae promis- 
come t o hand on 
agai. ) 
On the 8th of Angust last, a ve eruption was seen on the 
western slope of Mauna Loa, its . 
