Dr. Schafhaeult on Cast Iron, Steel, and Malleable Iron. 427 
The acid had scarcely been poured over the iron (B), when 
the whole powdered iron rose, under a rather violent evolution 
of gas, to the top of the acid. A short time after the acid be- 
came of a yellow colour, and the caseoid or cheese-like whitish 
foam increased each moment on the top of the acid during 
the evolution of hydrogen, and filling almost the whole of the 
upper part of the retort. 
In Woulfe’s bottles distinct glittering scales of sulphuret of 
lead were rapidly deposited ; the gas escaping out of the last 
bottle had, in an extremely slight degree, in smell the character 
of hydrogen developed by means of acids from iron, but no 
longer affected a solution of nitrate or acetate of lead. The 
liquid was found next day opake, of a light gray colour, 
still developing gas. 
The evolution from iron (A) had ceased long before. The 
iron (A) or white Welsh iron formed likewise a caseoid or 
cheese-like substance on the top of the acid, but its colour 
was dark gray approaching to black, and the liquid below was 
also of an opake dark gray. 
The sulphuret of lead formed in the Woulfe’s bottle was 
not scaly, like that from the gray iron, but resembling a dark- 
brown greasy viscid mass, making the whole liquid turbid, and 
only settling two days afterwards. The mass in the retort 
was then dark gray, with a somewhat lighter sediment. 
The residuum in the retort of the gray French iron (B) 
cast upon a filter, washed without interruption with boiling 
hot distilled water, was of a soap-like greasy form, and had 
after being dried a grayish-white flowery appearance. As 
often as I poured fresh water on the filter, the already col- 
lapsed mass began to swell like a sponge, and almost filled the 
whole filter. This residuum, dried at a temperature of 212° 
Fahr., weighed 5*53 grains, and had an extremely light ap- 
pearance resembling silica, chemically separated from mi- 
nerals. 
On 2*1 grains of powder were poured in a test-tube 5 
drachms of concentrated caustic ammonia, the test-tube shut 
with a perforated cork, which contained as usual an S-like 
bent glass tube; a violent evolution of gas in extremely 
minute bubbles took place, which ceased only twenty-four 
hours afterwards. The powder lay on the bottom of the test 
tube in lenticular aggregates of a gray colour; the evolved 
gas collected over water measured at 65^ Fahr. and 29’35 
height of barometer, 0*605 cubic inches, corrected for water 
0*586 cubic inches. It was, except small traces of oxygen 
and azote from the remaining air in the test tube, pure hydros 
gen. 
2 F 2 
