519 
Cast Iron, Steel, and Malleable Iron. 
I now proceed to show the results obtained when the above- 
mentioned residuum is treated, instead of acids, with caustic 
leys. 
14*88 grains of this residuum, powdered and boiled with 
strong caustic potash ley for ten minutes, lost 0*261 grains. 
When the ley was poured over the powder it foamed like soap 
suds. A little hydrogen was disengaged, emitting (during 
the whole boiling,) an odour partly resembling that of heated 
asphaltuni and partly that of fresh peat. Shortly after the 
boiling commenced, the powder appeared to be swimming in 
the clear liquid like distinct black scales, closely resembling 
so-called graphite scales, separated from gray cast iron ; but 
when dried on the filter, those scales resumed their former 
yellowish-brown colour, and looked again like powder, with- 
out any trace of scales remaining ; which again confirms my 
former assertion, that all residuums of iron dissolved in hydro- 
chloric acid, are separated in scales. 
14*619 grains of this boiled residuum, after being carefully 
heated, became dark-red brown, and had increased in 
weight 0*000 
After the second ignition it became light 
red, and had increased in weight . . 1*269 
After the third ignition it had increased 
in weight 0*608 
After the fourth ignition it had increased 
in weight 0*296 
After the fifth ignition it had increased in 
weight 0*222 
2*395” 
After being boiled in hydrochloric acid, only 0*6901 grains 
of a light gray colour remained. After a lively ignition it 
weighed only 0*4006 grains, which consisted of a distinct 
mixture of white and black grains. 
Another residuum of 14*88 grains, boiled with caustic pot- 
ash ley for more than thirty minutes, lost 0*325 grains. The 
remaining 14*555 grains, after being ignited had assumed 
a light red colour, and had increased . . 1*871 
Second time 0*486 
Third time 0*249 
Fourth time 0*000 
0*606 
During the process of boiling, the leys had extracted a mix- 
ture consisting of carbon, hydrogen, azote, and oxygen, with 
a very minute portion of silica. 35 grains of another specimen 
of Creuzot iron, whose specific gravity was = 7*305, treated 
