Cast Iron, Steel, and Malleable Iron. 5 1 9 



I now proceed to show the results obtained when the above- 

 mentioned residuum is treated, instead of acids, with caustic 

 ^eys. 



14'S8 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 

 asphaltum and partly that of fresh peat. Shortly after the 

 boiling commenced, the pow^der appeared to be swimming in 

 the clear liquid liiie 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 



