ANTHRAPURPURIN.

327

hypochlorite of soda, sp. gr. 1-036. No other red-dyed fabric will stand thistreatment, whereas the Turkey-red becomes more fiery and but very slightlyaltered in depth. Add to this, that it is not affetfted in the least by being im-mersed in dilute hydrochloric acid and in a solution of oxalic acid. Thepattern inserted at the top of the opposite page, for which we are indebted toMessrs. Steiner, Church, near Accrington, will give the reader an idea ofwhat this dye is like when properly executed. It is dyed with madder root,not with garancin or any other special preparation.

For comparison we also annex a specimen of Turkey-red dyed with Messrs.Perkin and Sons’ artificial alizarin, which we owe to the courtesy of Mr. W. H.Perkin.

This may also be the proper place to mention a new colour made knownafter the sedtion on the coal-tar derivatives was completed. We refer toanthrapurpurin—the latest discovery of Mr. W. H. Perkin. This substance,which is already largely used by calico printers, has nearly the same affinity formordants as alizarin, and the colours which it produces are analogous. Withalumina it yields a red, and with iron mordants purple and black. In the toneof the colours thus produced there is a considerable difference, the reds beingpurer and less blue than those obtained from alizarin, while the purples arebluer, and the blacks more intense. In fastness against soap and light thecolours are quite equal to those from alizarin. Its composition is—

Carbon .65-62

Hydrogen. 3-12

Oxygen .31-26

lOO'OO

corresponding to the formula C I4 Hg 0 3 . Anthrapurpurin, when heated, fuses,and then gives off orange vapours, which condense in yellowish-red leafletsor needles, though the largest part of the substance is carbonised. It issparingly soluble in alcohol and ether, but rather more freely in glacial aceticacid. In water it is very slightly soluble. If heated along with zinc-powderit yields a hydrocarbon which agrees in its properties with ordinary anthracen.If an ammoniacal solution of anthrapurpurin is heated to xoo°, in a sealedtube, for some hours, its colour changes from purple to indigo-blue. Thissolution, when acidified with hydrochloric acid, deposits a new produdt as adark purple precipitate, soluble in ammonia and in carbonate of soda with ablue colour, but in caustic alkalies with a reddish purple. It dyes aluminamordants purple, and weak iron mordants an indigo-blue. It is probablyisomeric with Stenhouse’s purpuramide. Solutions of anthrapurpurin incaustic potash always show the absorption-bands in the same region of thespedlrum, as do alkaline solutions of alizarin, but are less intense. Theammoniacal solution does not appear to give bands, nor does the etherealsolution of the colouring matter. In the latter case the violet is almostentirely absorbed.

A curious fadt, and which may serve to illustrate the adtion of oils as mor-dants, is related in a Dutch work, very little known, published a few yearss >nce, on Borneo and adjacent islands. The authors, a party of an exploringexpedition, found that whereas the very wild and barbarous tribes of a portion°f the country in question were utterly ignorant of any art approaching to