THE CULTIVATOR. 
193 
mers who prefer the French plaster to the Nova Scotia; 
and I have heard it said that that of our own State was 
much better than either. If this be true, it seems to be 
very poor policy to import from abroad an article which 
may be obtained better at home. 
Respectfully yours, Pierre V. C. Miller. 
Shawangunk, Ulster Co., March 18, 1844. 
PHILOSOPHY OF WOOL—No. Y. 
I have briefly treated thus far of the several valuable 
properties of wool; valuable, however, only as each con¬ 
tributes its part in the process of manufacture, and all se¬ 
condary or subordinate, yet in a measure essential to, the 
felting' power. 
The phenomena of felting long remained enshrouded 
in mystery. This gave rise to numerous speculations as 
to the primary cause or causes, many of which, although 
plausible at the time of their publicity, now that the true 
cause has been discovered, appear sufficiently ridiculous. 
But the keen sagacity of man at length mastered the sub¬ 
ject by surmising the correct theory, without the means, 
however, to demonstrate it, for want of microscopes of 
adequate power. To M. Monge, the distinguished 
French chemist, are we indebted for the first correct 
view of the structure of the fibre, which, from its pecu¬ 
liarity } mainly depends the felting principle. He asser¬ 
ted “ that the surface of each fibre of wool is formed of 
lamella}, or little plates which cover each other from the 
root to the point, pretty much in the same manner as the 
scales of a fish cover that animal from the head to the 
tail, or like rows placed over one another, as is observed 
in the structure of horns;” and he accounts for the felting 
process in the following way: 
“ In making a felt which is to constitute the body of a 
hat, the workman presses the mass with his hands, mo¬ 
ving them backwards and forwards in various directions. 
This pressure brings the hairs or fibres against each oth¬ 
er, and multiplies their points of contact. The agitation 
gives to each hair a progressive motion towards the root; 
but the roots are disposed in different directions—in every 
direction; and the lamellae of one hair will fix themselves 
on those of another hair, which happens to be directed a 
contrary way, and the hairs become twisted together, and 
the mass assumes the compact form which it was the aim 
of the workman to produce. If the wool is in cloth and 
subjected to the process of fulling, the fibres which com¬ 
pose one of the threads, whether of the warp or woof, 
assume a progressive movement: they introduce them¬ 
selves among those of the threads nearest to them, and 
thus by degrees all the threads become felted together, 
the cloth is shortened in all its dimensions, and partakes 
both of the nature of cloth and of felt. 3 ’ No language can 
be employed which will convey a more correct and viv¬ 
id impression of the process of felting, than the forego¬ 
ing. 
Through the indomitable perseverance of Mr. Youatt, 
the author of a valuable, though too diffuse, treatise on 
British sheep-husbandry, Monge's theory was finally de¬ 
monstrated, although he was often frustrated, and almost 
yielded to despair, from the imperfections of his instru 
ments. The construction at last of a superior achromatic 
microscope by Mr. Powell, of London, enabled him to 
realize his ardent wishes; and his own description of the 
scene, and the conclusions to which he arrived, are of 
too much interest to admit of any abbreviation. 
“ On the evening of the 7th of Feb. 1835, Mr. Thomas 
Plint, woolen manufacturer, resident at Leeds; Mr. Sy- 
monds, clothing agent, of London, Mr. F. Millington 
surgeon, of London, Mr. Edward Brady, veterinary sur 
geon, Mr. Powell, the maker of the microscope, and the 
author himself, were assembled in his parlor. The in 
strument was, in Mr. Powell's opinion, the best he had 
constructed. A fibre was taken from a Merino fleece of 
three year's growth; the animal was bred by, and be¬ 
longed to Lord Western. It was taken without selec¬ 
tion, and placed on the frame to be examined as a trans¬ 
parent object. A power of 300 (linear) was used, and 
the lamp was of the common fiat-wicked kind. The fo¬ 
cus was readily found; there was no trouble in the ad- 
pstment of the microscope; and after Mr. Powell, Mr. 
Plint had the first perfect occular demonstration of the 
irregularities in the surface of the wool, the palpable 
proof of the cause of the most valuable of its properties 
—its disposition to felt. 
“ The fibre thus looked at, assumed a flattened riband¬ 
like form. It was of a pearly grey color, darker towards 
the centre, and with faint lines across it. The edges 
were evidently hooked, or more properly serrated—they 
resembled the teeth of a fine saw. These were some¬ 
what irregular in different parts of the field of view, both 
as to size and number. The area of the field was now 
ascertained; it was one-fortieth of an inchin diameter. 
By means of the micrometer we divided this into four, 
and we then counted the number of serrations in each di¬ 
vision. Three of us counted all four divisions, for there 
was a difference in some of them. The number was set 
down privately, and it was found that we had all estima¬ 
ted it at fifteen in each division. Having multiplied this 
by four, to obtain the whole field, and that by forty, the 
proportionate part of an inch of which the field consist¬ 
ed, we obtained a result which could not be disputed, that 
there were 2,400 serrations in the space of an inch, and 
all of which projected in the same direction, viz. from 
the root to the point. Then, before we quitted the exa¬ 
mination of the fibre as a transparent object, we endea¬ 
vored to ascertain its actual character, and proved it to 
l-750th of an inch. 
“ We next endeavored to explore the cause of this ser¬ 
rated appearance, and the nature of the irregularities on 
the surface, which might possibly account for the pro¬ 
duction of these tooth-like projections; we therefore took 
another fibre, and mounted it as an opaque object. There 
was considerable difficulty in throwing the light advan¬ 
tageously on the fibre, so small a. space only as l-30th 
of an inch intervening between the lens and the object. 
At length Mr. Powell perfectly succeeded; and we were 
presented with a beautiful glittering column, with lines of 
division across it, in number and distance seemingly cor¬ 
responding with the serrations that we had observed in the 
other fibre that had been viewed as a transparent object. 
It was not at once that the eye could adapt itself to the bril¬ 
liancy of the object; but by degrees these divisions develo¬ 
ped themselves, and could be accurately traced. These 
were not so marked as the inverted cones which the bat’s 
wool presented, but they were distinct enough; and the 
apex of the superior one, yet comparatively little dimin¬ 
ished in bulk, was received into the excavated base of 
the one immediately beneath, while the edge of this base 
formed into a cup-like shape, projected, and had a serra¬ 
ted, or indented edge, bearing no indistinct resemblance 
to the ancient crown. All these projecting indented 
edges pointed in a direction from root to point. 
« Whether these, like the cones of the bat, are joints, 
or at least points of comparative weakness, and thus ac¬ 
counting for the pliancy and softness of the fibre, or reg¬ 
ulating the degree in w r hich these qualities exist, may 
perhaps be better determined by and by; one thing, 
however, is sufficiently plain, that these serrated edges in 
the transparent object produced (when the fibre was re¬ 
solved into its true form as an opaque one) by the pro¬ 
jecting edges of the cups or hollowed bases of the inver¬ 
ted cones, afford the most satisfactory solution of the felt¬ 
ing principle that can be given or desired. The fibres 
can move readily in a direction from root to point, the 
projections of the cups offering little or no impediment, 
™ pwm mss but when they havc 
fj\\m AjJfljilu been once involved 
that has been pressed 
powerfully together, 
as in some part of the 
manufactory of all 
felling w r ool, the re¬ 
traction of the fibre 
must be difficult, and 
in most cases impos¬ 
sible.” 
The annexed cuts 
exhibit microscop¬ 
ic views of fibres of 
No. 4. wool from picklock 
