British Association for the Advancement of Science. 303 
but.one species of the general effects which usually occur in chem- 
_leal actions, all of which are modifications . universal etic 
arising from circumstances. 
Mr.. William Herapath gave a paper. on a new process. for tae 
ning. He assumed that the great cause of obstruction to rapid 
tanning, is, that the weakened ooze is retained by the capillary 
attraction of the. fibres and blood-vessels so long, that when it 
shall. have passed out by exosmosis, it will have produced the 
same effect upon the soluble gelatin as is produced by maceration. 
Hydraulic pressure was too expensive, and he accordingly thought 
of employing pressure by the roller. . 
On the application of gas obtained by Water to the cantonal: 
ture of Iron, by Mr. J. S. Dawes. The mode is as follows. Jets 
of steam are made to pass through red hot cast-iron pipes, filled 
‘with small coke or charcoal; decomposition immediately takes 
place; the base of the. carbon of the coke combines with the ox- 
ygen base of the steam, forming, at first, carbonic acid, but by 
passing this over.a further portion of red. hot carbon, it is con- 
verted into carbonic oxide, sensible heat at the same time becom- 
ing latent on combining with the hydrogen base, producing hy- 
drogen gas, which, together with the oxide -before mentioned, is 
applied to the furnace by means of a-jet inserted within the blast- 
“pipe tuyere, the prenenne of the gas, of course, being oan to that 
upon the blast. . - 
A description,. by Prof. Miller, was next prec of an improve- 
ment in the construction of the rails Gontometer, by salvinh 
it is rendered more portable. 
, Drv: Thomson gave an aapgtink of Galoctin, a substance 
which constitutes, the principal ingredient in the sap of the Cow 
tree, or Galactodendron utile of South America. ~The. sap, on 
standing, throws up.a white matter, soluble in boiling alcohol, 
but deposited as that liquid-cools. . When well washed and dud 
in vacuo, over sulphuric acid, it constitutes galactin. It is yel- 
low, translucent, and brittle, has a resinous aspect and is tasteless, 
It is insoluble in water, but soluble in alcohol and ether. Gravity, 
0.969... It dissolves readily in oil of turpentine and. olive oil. It 
is composed of 6 atoms carbon, 4.5+6 atoms hydrogen, .75+41 
atom oxygen, 1, = 6.25, being isomeric with Brazil wax. r 
The secretary, Prof. Miller, read a paper on Lieut. Morrison’s 
instrument for measuring the electricity.of the atmosphere, and 
