392, Notes and Correspondence. 
pods, oats, and even wheat, must be 
named before it on the list of foods 
for the stable, feeding stall, or sheep- 
fold. And, if the mixed malt and 
linseed, both of them relaxing sub- 
stances, which are offered to him 
duty free, be experimented on by the 
cattle-feeder, he must add a large 
proportion of bean meal, or some 
other astringent substance, to cor- 
rect a tendency which will rather 
check than help the fattening pro- 
cess ; while if used merely to induce 
the saccharine fermentation in other 
meals, which would form the bulk 
of the food administered, the small 
quantity wanted for that purpose is 
not worth the legislation which has 
been demanded for it. The real 
object of the existing agitation on 
this subject no doubt is, that we 
may have malt free for man. And 
the point, practically worthless and 
unimportant, but theoretically inde- 
fensible, which was pointed out 
by Mr. Williams to Mr. Gladstone, 
and on which the present Bill is 
founded, will have served a useful 
purpose if it shall in any degree 
have helped to remove what is un- 
doubtedly a demoralizing, and, ex- 
cepting to the tenants of good bar- 
ley-growing districts, a generally 
mischievous impost. 
J. C. Morton, 
Ed. ‘ Agricultural Cyclopedia,’ 
March, 1864. 
A New Method of Illustrating the 
Structure of Blister Steel, by Nature 
Printing. By H.C.Sorby, F.R.S, 
BroomFie.D, near Sheffield, 
March, 1864. 
WHEN iron is converted into steel 
by cementation, three distinct crys- 
talline compounds are formed, two 
of which are readily dissolved by 
diluted nitric acid, whereas one is 
scarcely at all affected by it. If, 
therefore, a piece of such steel be 
ground flat and polished, and then 
placed in the acid, after a suitable 
[ April, 
amount of action, this constituent 
retains its original surface and po- 
lish, whereas the other two are so 
much dissolved that it stands up 
in sufficient relief to allow of the 
blocks being used for surface print- 
ing instead of a woodcut, to exhibit 
the structure of different varieties 
ofsteel. At the late conversazione 
of the Sheffield Literary and Philo- 
sophical Society, specimens were 
printed showing the appearance 
of a square bar of iron once con- 
verted (transverse section), iron 
remaining in the centre; a flat 
bar of iron, slightly converted, the 
crystals being small; a square bar 
of iron twice converted (transverse 
section), showing the centre incom- 
pletely converted ; a flat bar of iron, 
highly converted, the crystals being 
rather large ; a round bar of “‘ homo- 
geneous metal,” converted (trans- 
verse section); and a flat bar of 
hammered cast steel, reconverted, 
the crystals being very large. In 
order that you may convey to your 
readers some idea of the appear- 
ances thus presented, I send you 
herewith a small block of prepared 
metal, capable of being employed 
as a woodcut. 
It is a transverse section of “ blister 
steel,” from a flat bar of iron highly 
converted. The best method of 
viewing the prints is by mounting 
them as stereoscopic objects, for 
they appear to great advantage un- 
der such a magnifying power. 
Though far more suitable for blister 
steel than for any other metal, yet 
still prints may be obtained from 
sections of armour-plates and other 
varieties of iron, which show cer- 
tain peculiarities in their structure 
in a very satisfactory manner. 
H. C. Sorsy, F.RS., &c. 
OE OEE 
