90 W. G. Mixter—Estimation of Sulphur in Coal. 
On this island I have never seen any boulders of fossiliferous 
rock. They have, however, been seen by others. On the Jersey 
side I have seen them from the Corniferous limestone of the 
Roundout valley. Now, as this rock is not seen in the lower 
this class of evidence we may notice the boulders of granular 
gneiss from Archean rocks of the Highlands, which I have 
found as far east as East New York. 
On the island of New York, in the deep excavations for sub- 
cellars for blocks of buildings, we often find modified drift, 
to the depth of twenty to thirty feet, entirely composed of clean 
washed sands—derived from the sandstones of New Jersey. 
New York, 24 Pine St., June 17, 1872. 
a) 
Art. XVI—Contributions from the Laboratory of the Sheffield 
Scientific School. No. XXIV.—On the Estimation of Sulphur 
in Coal and Organic Compounds; by W. G. MIxTER. 
THE determination of sulphur in organic substances by many 
of the methods in use is not only a difficult and tedious operation, 
but the amount of fixed reagents often employed greatly in- 
creases the liability to error. In the process here described, sub- 
stances are burned in oxygen and the sulphur is condensed 
from the gaseous products in the form of sulphuric acid. 
Experiments made by passing the products of combustion of 
sulphur-compounds through nitric acid failed to give satisfactory 
results. A variable loss was due to a dense white fume containing 
avoid this source of error. The bottle (a), see figure, has a : 
capacity of from 4 to 10 litres, according to the amount of oxy- 
gen required. The neck should be large enough for a oe 
35 to 40 mm. in diameter. The condenser 6 is made of rather 
thin tubing 14 mm. in diameter; at the upper end it is ex- 
panded to a bulb in order to admit some motion to the tube 
ed. Below the bulb it is surrounded by a water-jacket 22 cm. 
high: from the point where it enters the stopper of the bottle it 
is narrowed somewhat for convenience of fitting. The combus- 
tion tube c d is made of hard glass of 12-15 mm. internal dia- 
meter; the portion c is 18 em. from curve to curve, and is pro- 
tected by a sheet-iron trough lined with asbestos; the part d 18 
fom 35 to 45cm.in length. The wire attached at / is to sustain — : 
