BULLETIN OF THE BUSSEY INSTITUTION. 25 
dilute chlorhydric acid, separating iron and alumina by means of ammo- 
nia and precipitating lime in the filtrate as an oxalate. 
For the analyses of the deep-sea muds, the samples were dried at 100° C. ; 
the solution in strong hot chlorhydric acid was evaporated to dryness 
upon a water bath to separate silica; iron and alumina (together with 
manganese when present) were thrown down by means of ammonia; and 
the lime by means of oxalate of ammonia in the usual way. 
In case the appearance of the carbonate of lime or the caustic lime 
obtained on ignition was unsatisfactory, the product was redissolved in 
dilute acid, the solution was filtered, and the lime was reprecipitated 
from it. The filtrate from the lime was divided into two portions, in 
one of which magnesia was determined as pyrophosphate; and in the 
other potash, as chloroplatinate. Phosphoric acid was determined by 
fusing the iron and alumina precipitate with carbonate of soda, and 
treating the nitric-acid solution of the fused mass with molybdate of 
ammonia, as described above. 
I am indebted to my friend, Professor N. S. Shaler, for advice and 
counsel concerning the names of rocks; and to Messrs. F’. P. Pearson, 
of Lowell, J. A. Beatley, and F. W. Very, for collecting many of 
the specimens. Several of the analyses were performed by Messrs. 
Beatley and Very, formerly my assistants, but most of them by Mr. 
Henshaw, as has been stated above. 
