Micrographia, by Robert Hooke

Observ. iii. Of fine Lawn, or Linnen Cloth.

This is another product of Art, A piece of the finest Lawn I was able to get, so curious that the threads were scarce discernable by the naked eye, and yet through an ordinary Microscope you may perceive what a goodly piece of coarse Matting it is; what proportionable cords each of its threads are, being not unlike, both in shape and size, the bigger and coarser kind of single Rope-yarn, wherewith they usually make Cables. That which makes the Lawn so transparent, is by the Microscope, nay by the naked eye, if attentively viewed, plainly enough evidenced to be the multitude of square holes which are left between the threads, appearing to have much more hole in respect of the intercurrent parts then is for the most part left in a lattice-window, which it does a little resemble, onely the crossing parts are round and not flat.

These threads that compose this fine contexture, though they are as small as those that constitute the finer sorts of Silks, have notwithstanding nothing of their glossie, pleasant, and lively reflection. Nay, I have been informed both by the Inventor himself, and several other eye-witnesses, that though the flax, out of which it is made, has been (by a singular art, of that excellent Person, and Noble Vertuoso, M. Charls Howard, brother to the Duke of Norfolk) so curiously dress'd and prepar'd, as to appear both to the eye and the touch, full as fine and as glossie, and to receive all kinds of colours, as well as Sleave-Silk; yet when this Silken Flax is twisted into threads, it quite loseth its former luster, and becomes as plain and base a thread to look on, as one of the same bigness, made of common Flax.

The reason of which odd Phenomenon seems no other then this; that though the curiously drest Flax has its parts so exceedingly small, as to equallize, if not to be much smaller then the clew of the Silk-worm, especially in thinness, yet the differences between the figures of the constituting filaments are so great, and their substances so various, that whereas those of the Silk are small, round, hard, transparent, and to their bigness proportionably stiff, so as each filament preserves its proper Figure, and consequently its vivid reflection intire, though twisted into a thread, if not too hard; those of Flax are flat, limber, softer, and less transparent, and in twisting into a thread they joyn, and lie so close together, as to lose their own, and destroy each others particular reflections. There seems therefore three Particulars very requisite to make the so drest Flax appear Silk also when spun into threads. First, that the substance of it should be made more clear and transparent, Flax retaining in it a kind of opacating brown, or yellow; and the parts of the whitest kind I have yet observ'd with the Microscope appearing white, like flaw'd Horn or Glass, rather then clear, like clear Horn or Glass. Next that, the filaments should each of them be rounded, if that could be done, which yet is not so very necessary, if the first be perform'd, and this third, which is, that each of the small filaments be stifned; for though they be square, or flat, provided they be transparent and stiff, much the same appearances must necessarily follow. Now, though I have not yet made trial, yet I doubt not, but that both these proprieties may be also induc'd upon the Flax, and perhaps too by one and the same Expedient, which some trials may quickly inform any ingenious attempter of, who from the use and profit of such an Invention, may find sufficient argument to be prompted to such Inquiries. As for the tenacity of the substance of Flax, out of which the thread is made, it seems much inferiour to that of Silk, the one being a vegetable, the other an animal substance. And whether it proceed from the better concoction, or the more homogeneous constitution of animal substances above those of vegetables, I do not here determine; yet since I generally find, that vegetable substances do not equalize the tenacity of animal, nor these the tenacity of some purified mineral substances; I am very apt to think, that the tenacity of bodies does not proceed from the hamous, or hooked particles, as the Epicureans and some modern Philosophers have imagin'd; but from the more exact congruity of the constituent parts, which are contiguous to each other, and so bulky, as not to be easily separated, or shatter'd, by any small pulls or concussion of heat.

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Last updated Monday, March 17, 2014 at 16:42