1852.] OF THE ROYAL INSTITUTION. 135 
The result of this agency of soda was, as formerly remarked, a 
physical corrugation, and an acquisition of certain chemical qualities. 
The former change was evident to the eye. Dr. Playfair exhibited 
two stockings, one of which being nearly double the size of 
the other, although both came equal in size from the loom. 
The difference had been occasioned solely by chemical not me- 
chanical agency. Dr. Playfair, in developing the numerous practical 
applications of this physical effect, showed that, besides the most 
obvious one of producing a material of increased fineness, the cotton 
thus prepared was far more capable of being dyed. Hot soda solu- 
tion would not answer; and this fact was remarkable and had its 
analogue in those salts which deposited themselves anhydrous on 
boiling. Instead of soda sulphuric acid might be employed; in 
which case it formed, in combination with the cotton fibre, an easily 
decomposable conjugate acid. 
B.—Some years ago Liebig stated that one of the greatest discoveries 
of chemistry would consist in converting coal-gas into a solid form, 
thus enabling it to be burned like a candle. This had, in a manner, 
been accomplished by Mr. Young. About three years since, Dr. 
Playfair drew the attention of Mr. Young to a spring of mineral oil, 
containing paraffine, and occurring in a coal-mine in Derbyshire. 
The liquid had been extensively applied by Mr. Young as a lubrica- 
ting agent; a use which Reichenbach had long ago suggested, 
After a period, however, this spring ceased to flow, when Mr. 
Young applied himself to an investigation of the theoretical con- 
ditions under which it might be artificially formed. This gentle- 
man saw that it would be difficult to convert gas into an allotropic 
form, whereas it was evident that gas must first come from a 
solid ; hence he hoped to succeed in procuring the body before it 
assumed its gaseous state. 
The illuminating portion of coal gas consists chiefly of olefiant 
gas, and the latter is isomeric with solid paraffine. But the allo- 
tropism does not end here; the peculiar slow distillation of coals 
yielding solid paraffine, also yielded another isomeric or allotropic 
compound in the form of a lubricating oil, besides the additional 
products of a burning oil, and naphtha. 
Dr. Playfair now explained, by the aid of a diagram, the slow 
distillation process of Mr. Young, employed in generating his allo- 
tropic form of olefiant gas, and directed the attention of his audience 
to some candles made of coal paraffine on the lecture table. 
C.— Schrétter’s process of manufacturing amorphous or allotropic 
phosphorus was the third in Dr, Playfair’s series. The properties 
of phosphorus in its ordinary condition are well known. It is spon- 
taneously inflammable and highly poisonous ; whereas the amorphous 
or allotropic phosphorus is neither spontaneously inflammable nor 
poisonous. Hence its great use in the manufacture of lucifer and 
congreve matches ; an operation which not only imperilled the pre- 
mises wherein it is conducted, but also the lives of those conducting 
it, causing the most frightful and fatal disease of the jaws and 
facial bones. 
Common phosphorus, when heated to about 460 or 480, changes 
