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Part 4 (1/2)

The Che Watson Smith 146370K 2022-07-20

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of | of |= 12 |012 lb | |alpha- | | | lb of | Aniline |Toluidine|lb of|of Xylene | |Naphthylamine | | |Alizarin| | |Aurin|= 007 lb| |= 711 lb of | | | (20) | | | |of | |Vermilline | | | | ________________/ | |Xylidine | |Scarlet | | | | = 0623 lb of | | | |RRR; or 475 | | | | Magenta | | | |lb of | | | | | | | | |alpha- | | | | or 110 | | | | |or beta- | | | | lb of | | | | |Naphthol | | | | Aniline | | | | |= 950 lb of | | | | yields | | | | |Naphthol | | | | 123 lb | | | | |Yellow| | | | of Methyl| | | | | | | | | Violet | | | | | | | | | ---------+---------+------+----------+----+--------------+---+---+--------+----

[Footnote 2: This table was compiled by Mr Ivan Levinstein, of Manchester]

The next table (see Table B) shows you the dyeing power of the colouring matters derived frohtful enta will dye 500 yards of flannel, the Aurin 120 yards, the Vermilline Scarlet 2560 yards, and the Alizarin 255 yards (Turkey-red cotton cloth)

The next table (Table C) shows the latent dyeing power resident, so to speak, in 1 lb of coal

By a very simple experiment a little of a very fine violet dye can be made from mere traces of thethis violet dye is a substance with a long name, which itself was prepared from aniline This substance is tetramethyldiamidobenzophenone, and a little bit of it is placed in a slass test-tube, just moistened with a couple of drops of another aniline derivative called di liquid, trichloride of phosphorus, added On si this mixture, the violet dyestuff is produced in about a e cylinder of water a beautiful violet

The remainder (perhaps two drops ht full shade of violet Here, then, is a nificent example of enormous tinctorial power I h a perfect wonderland of , without, however, an adequate return of solid instruction that you can carry usefully with you into every-day life and practice

TABLE B[3]

------------------------------------------------------------------------------- DYEING POWERS OF COLOURS FROM 1 TON OF LANCAshi+RE COAL

|violet |yellow | | | ------------+------------+------------+-------------+-------------+------------

TABLE C[3]

------------------------------------------------------------------------------- DYEING POWERS OF COLOURS FROM 1 LB OF LANCAshi+RE COAL

[Footnote 3: These tables were compiled by Mr Ivan Levinstein, of Manchester]

Before we go another step, I et soeneralcoal-tar colours which serve as types of whole series? I will try what can be done with the little knowledge of chemistry we have so far accumulated In our earlier lectures we have learnt that water is a coen, and in its coen coen, symbolised as H_{2}O We also learnt that aen with nitrogen, three atoen, thus, NH_{3} An exaen, is as (methane) or firedamp, CH_{4} Nitric acid, or _aqua fortis_, is a coen, one atom of the first to three of the second and one of the third--NO_{3}H But this nitric acid question forces me on to a further statement, namely, we have in this formula or symbol, NO_{3}H, a twofold idea--first, that of the compound as a whole, an acid; and secondly, that it is formed from a substance without acid properties by the addition of water, H_{2}O, or, if we like, HOH This substance contains the root or radical of the nitric acid, and is NO_{2}, which has the power of replacing one of the hydrogen atoet, instead of HOH, NO_{2}OH, which is nitric acid This is chemical replace up not only colours, but many other useful and ornamental chemical structures You have all heard the old-fashi+oned statement that ”Nature abhors a vacuum” We had a very practical exaht an electric spark in contact with a ases at once united, three voluain to a minute particle of liquid water A vacuulass bulb whilst the pressure of the at with a force of 15 lb on the square inch on the outside of the bulb, and thus a violent crash was the result of Nature's abhorrence There is such a kind of thing, though, and of a ht term a chemical vacuum, and it is the result of e call cheht be defined as the specific chemical appetite of each substance

Let us now take the case of the production of an aniline colour, and let us try to discover what aniline is, and how formed I pointed to benzene or benzol in the table as a hydrocarbon, C_{6}H_{6}, which for constituent of coal-tar If you desire to produce chemical appetite in benzene, you roup that would exist only for a reat appetite for H, and we th of at once absorbing either one ato a similar appetite Suppose, now, I place some benzene, C_{6}H_{6}, in a flask, and add so the s up in that OH of the nitric acid to effect union with an H of the C_{6}H_{6} (benzene) to form HOH (water), when an appetite is at once left to the remainder, C_{6}H_{5}--on the one hand, and the NO_{2}--on the other, satisfied by immediate union of these residues to form a substance C_{6}H_{6}NO_{2}, nitro-benzene or ”essence oflike bitter almonds This is the first step in the formation of aniline

I think I have told you that if we treat zinc scraps ater and vitriol, or water with potassiuen It is, however, a singular fact that if we liberate a quantity of fresh hydrogen aen tends to coovernable appetite for the O_{2} of that NO_{2} group, the tendency being again to form water H_{2}O This, of course, leaves the residual C_{6}H_{5}N: group with an appetite, and only the excess of hydrogen present to satisfy it Accordingly hydrogen is taken up, and we get C_{6}H_{5}NH_{2} formed, which is aniline I told you that ammonia is NH_{3}, and now in aniline we find an a replaced by the group C_{6}H_{5} I will now describe the method of preparation of a small quantity of aniline, in order to illustrate what I have tried to explain in theory Benzene fro action sets in, and on adding water, the nitrobenzene settles down as a heavy oil, and the acid water can be decanted off After washi+ng by decantation ater once or twice, and shaking with some powdered ht into contact with fresh hydrogen gas by placing ast it, instead of zinc, some tin, and instead of vitriol, some hydrochloric acid (spirits of salt) To show you that aniline is formed, I will now produce a violet colour with it, which only aniline will give This violet colour is produced by adding a very s powder, to aadded for the purpose of destroying acidity This aniline, C_{6}H_{5}NH_{2}, is a base, and forms the foundation of all the so-called basic aniline colours If I have made myself clear so far, I shall be contented It only reenta, pure aniline will not do, what is used being a her, prepared froenta you would be astonished at its complexity and size, but I think now you will see that it is really built up of aniline derivatives Methyl Violet is a colour we have already referred to, and its chemical structure is still more complex, but it also is built up of aniline materials, and so is a basic aniline colour Now it is possible for the colour-reen dye from this beautiful violet (Methyl Violet) In fact hethe first under pressure with a gas called methyl chloride (CH_{3}Cl) Methyl Violet is constructed of aniline or substituted aniline groups; the addition of CH_{3}Cl, then, gives us the Methyl Green But one of the misfortunes of Methyl Green is that if the fabric dyed with it be boiled ater, at that temperature (212 F) the colour is decomposed and injured, for some of the methyl chloride in the co we inal Methyl Violet back again

But we have coal-tar colours which are not basic, but rather of the nature of acid,--a better term would be _phenolic_, or of the nature of phenol or carbolic acid Let us see what phenol or carbolic acid is We saw that water may be formulated HOH, and that benzene is C_{6}H_{6}

Well, carbolic acid or phenol is a derivative of water, or a derivative of benzene, just as you like, and it is for carbolic acid or phenol down a red-hot tube filled with iron-borings The oxygen is taken up by the iron to give oxide of iron, and benzene is obtained, thus: C_{6}H_{5}OH gives O and C_{6}H_{6} But there is another hydrocarbon called naphthalene, C_{10}H_{8}, and this forms not one, but two phenols As the name of the hydrocarbon is naphthalene, however, we call these couished as alpha- the other as beta-naphthol, both of the the formula C_{10}H_{7}OH But noith respect to the colours If we treat phenol with nitric acid under proper conditions, we get a yellow dye called picric acid, which is trinitro-phenol C_{6}H_{2}(NO_{2})_{3}OH; you see this is no aniline dye; it is not a basic colour, for it would saturate, _ie_ destroy the basicity of bases Again, by oxidising phenol with oxalic acid and vitriol, we get a colour dyeing silk orange, namely, Aurin, HOC[C_{6}H_{4}(OH)]_{3} This is also an acid or phenolic dye, as a glance at its formula will show you Its compound atom bristles, so to say, with phenol-residues, as soroups

We coroup of colours known as the azo-dyes, and these can be basic or acid, or of roups, NH_{3} and NH_{3} If we rob those nitrogen atoen atoen atoly keen appetite represented in terroup, though of two N atoms partially satisfied by partial union with each other, thus--N:N--

Now this group foren at one side with an aniline, and at the other with a phenol, or at both ends with anilines, and so on, we get azo-dyes produced The nureat, and the variety also

_Adjective Colours_--As regards the artificial coal-tar adjective dyestuffs, the principal are Alizarin and Purpurin These are now almost entirely prepared froarancine are aletable adjective colours are Brazil wood, containing the dye-generating principle Brasilin, logwood, containing Hae Santalin

Animal adjective colours are cochineal and lac dye Then of wood colours we have further: quercitron, Persian berries, fustic and the tannins or tannic acids, coallnuts, with also leaves and twigs, as with su with certain htly-coloured compounds on the tissues to which they are applied

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