Dictionarium polygraphicum. Purple.

Dictionarium Polygraphicum:
Or, The Whole Body of Arts Regularly Digested.
Vol II.
London: Printed for C. Hitch and C. Davis in Pater-noster Row, and S. Austen in St. Paul's Church Yard. MDCCXXXV.
1735
PURPLE is a red colour bordering on violet, made principally with cochineal or scarlet grain.

Purple was in high esteem among the ancients, especially the Tyrian purple, which pass'd through more dyes than the rest; and which colour was in a manner almost peculiar to kings and emperors.

Yet this purple did not exceed that now in use; the chief reasons wny the former has been difus'd, are, that our modern purple is not only cheaper, but finer.

The ancient or Tyrian purple was tinged or dyed with the blood of a testaceous shell-fish, which the Latins call purpura.

There is now found about Nicoya in the Spanish West-Indies a shell-fish, which perfectly resembles the ancient purpura, and is in all probability the very same.

Gage relates of this fish, that it usually lives seven years; that it hides itself upon the approach of the dog-days, and continues hid for 300 days running.

These fishes are gather'd plentifully in the spring, and by rubbing one against another, yield a kind of saliva or thick glair, resembling soft wax; but the purple dye is said to be in the throat of the fish, and the finest part in a little white vein; the rest of the body is of no use. He adds, that the chief riches of Nicoja consists in this fish.

Cloth of Segovia, dyed with this purple liquor, is sold for 20 crowns the ell, and is worn by none but the greatest Spanish Lords.

Besides the West-Indian purple fishes, we have others much nearer home; and Mr. W. Cole did in the year 1686, discover purple fishes on the coasts of Somersetshire, South-Wales, &c. where they were found in great abundance, as we find in the Philosophical Transactions.

Mr. Reaumer observes, that this fish is a kind of buccinium, by which name the ancients call'd all those shell fishes, that bear any resemblance to a hunting-horn; and, as Pliny relates, the ancient purple was taken from this kind of shell-fish.

The author describes the method of obtaining the colour as follows; they break the shell, which is very hard, holding the mouth of the fish downwards, so as not to crush the body; and pick off the broken pieces, and then there appears a white vein, lying transversly in a little furrow or cleft, next the head of the fish.

In this vein is the purple liquor lodg'd; some of which being laid on linnen, appears at first of a light green colour; but if expos'd to the sun, soon changes into a deep green, and in a few minutes more into a sea-green, and in a sew more into a blue; thence it soon becomes of a purplish red, and in an hour more of a deep purple red.

And here the action of the fun ends; but it becomes of a most bright, beautiful crimson, by being wash'd in scalding water and soap, which will bear washing admirably without any styptick.

Mr. Reaumer has discovered another very different kind of purple. This, he fays, is produc'd in oval grains about a quarter of an inch long, and one inch thick, full or a white liquor, bordering on yellow, which cover certain stones or sands, abouc which the fish call'd buccina of Poictou in France usually assemble.

These he supposes to be the eggs of some unknown fish.

These grains being bruis'd on a white linnen cloth, at the first only tinge it yellow, and that insensibly, but in three or four minutes turn to a very beautiful purple red; provided the linnen be expos'd to the open air; for the air of a room, altho' the windovs be open, will not produce this effect.

This colour will fade a little by repeated washings.

There is likewise a purple fish about the Caribbee Islands; this fish is call'd Burgan, being much about the size of the end of a finger, and in shape like our periwinkles: the shell of it is of a brownish azure, the flesh white, the inwards of a very bright red, the colour of which appears through the body; and it is this that dyes the froth, which it casts forth when taken, and which at first is of a violet hue, bordering on blue.

To cause these fish to yield the greater quantity of froth, they lay them on a plate, shake and beat them one against another; upon which the plate is immediately cover'd with the froth, which they receive on a linnen cloth, and as it dries becomes purple.

P. Labat observes, that this colour is found to dwindle and dissipate in proportion as the linnen that is dyed with it is wash'd.

The same author gives us also the description of another purple dye, produc'd by a plant that grows in the Antilles islands: the juice of this tree, when cut, he fays, is of a blood-red colour, and communicates the same colour to cloths; tho' like the former it loses much in washing.