Thanks for your note. Yes, I do like the white oil, but I add copal to it if I want it to be very drying, or mix copal on the palette with a slow-drying colour, say a lake. This, I suppose, is all right; if so, don't trouble to acknowledge this. The oil of orange is delightful on account of its smell, but dries less quickly than turpentine (rectfd. spirit). Is it not _always_ better to have _some_ resin in a picture _throughout_ since it has to be varnished at the end?

_April 21, 1888._

I am so much enamoured with the method, so far as vehicle is concerned, which I have used during the last year, that I should like to feel quite certain that it is _absolutely safe_. I use a "single-primed" canvas, and underpaint with "Bell's medium" and rect. spir. turps., which, under your advice, I have in _small_ bottles, so that using it freely a bottle lasts a very short time, and the stuff is therefore always fresh. The mixture I _use up to the end_ (except when I now and then use the pigment _alone_), and letting the turps. rather _preponderate_ as I advance. I have found to my amazement that this mixture dries even in winter weather excellently, and that I can use with it even scarlet madder and aureolin, which, at least the former, hitherto I never attempted to use except stiffened with amber or copal; and I further find that this mixture, though of course it "sinks" to some extent (and especially with the blues), in the main bears up very fairly, incomparably better than I should have expected, and in fact quite enough. Before beginning to paint I rub over the part each time with Bell's medium and saliva nearly equal parts, or say five oil to four saliva beaten up with the knife on the palette to a white mucilage. This, if left alone, makes a good varnish, and is delightful to paint into. So far, so good; at least I suppose so. (Do you see any elements of danger? cracking? darkening?) But at the end something must go over it all, if only to lock it up (I suppose), certainly to get uniform gloss and strength. I propose in the Academy to put Roberson's medium over the whole of my large one and to retouch with the same. A portrait on to which I _don't_ intend to work I should cover with mastic and _a little poppy oil_; there is no harm in this, I suppose, and the small quant.i.ty of mastic is not likely to yellow, is it? I know this mixture _won't come off_, but why should it?

_May 30, 1889._

Messrs. Reeves send me a colour in which I delight, but which I have hitherto always avoided as being unsafe, to wit, indigo. I suppose one ought not to use it, ought one? although my old friend, and in some ways my master, Robert Fleury, employed it extensively in _underpainting_ blue draperies.

_December 23, 1889._

I have got a recipe--a very simple one--from a friend of mine in Italy, who paints a good deal in distemper, and who in technical matters is quite the most leery person I ever came across. In this recipe he mentions what he calls "Gum Damar," which he, in his characteristic ignorance of spelling (for Italians are not very strong in orthography), writes with an apostrophe, D'Amar.

Now I presume he means "Gum Dammar" (I believe there is such a thing, is there not?), but I should like to feel sure. Perhaps you will kindly enlighten me on a post-card.

The distemper itself is the simplest thing in the world. It is only a proportion of water and yolk of egg (he deprecates the use of vinegar), to which he adds a certain number of drops (I have not the recipe by me) of this gum. Of course it would be important not to use the wrong gum. Hence the trouble I am giving you.

_January 27, 1890._

I have just received from Perugia the enclosed sample of Gum Dammar, which you were kind enough to say that you would report upon to me. A few drops of this (by-the-bye, I do not know how it is to be dissolved) and the yolk of an egg stirred in water, form the distemper used by my friend Mariani.

I don't know whether I told you that he is rather an interesting fellow. He is one of those extremely dexterous Italian workmen-artists who know and can work in every material, and whose forgeries of sixteenth century bric-a-brac, ca.s.soni, reliefs in pastiglia, &c. &c., have, I am afraid, not infrequently been purchased as original by very crafty persons.

Several friends of mine who use distemper, and he amongst the number, tell me that by putting a preparatory coating of distemper over thoroughly dry oil, you can with perfect safety interpose a layer of _painting_ in distemper between two paintings in oil--an extremely valuable thing for us _for recovering quality_.

_January 31, 1890._

Many thanks for your valuable letter. I have had the information entered in a little book, where I keep the outpourings of your wisdom on matters chemical.

Thanks also for the card, in which you give me a somewhat long name for my Gomme Dammar. I suppose in an appeal to a chemist the _first_ portion would suffice.

_February 14, 1890._

Many thanks for your valuable note. I may say in pa.s.sing that the specimen of "Ruby Madder" sent by Mr. Laurie appears to me to be inferior in brilliancy to both the Rose Madder and the Madder Carmine furnished by Messrs. Roberson; and I have no reason to doubt that the latter colours are perfectly trustworthy.

It will give me great pleasure to receive the dedication of your book, which I look forward to seeing with pleasure, and using with profit.

_May 19, 1890._

Many thanks for your note, which seems to open up an interesting point. I gather from what you say that the mode of _manufacture_ of a colour may affect its drying properties over a range extending from drying very slowly to drying very rapidly; and I shall be much interested in hearing what your experiments lead to under this head.

_January 30, 1891._

Many thanks for your letter. I see that I had better wait for a final opinion until the few months have expired which you still require as tests of permanence. Meanwhile, I am a little unhappy to see in the case of colour after colour the expression "semi-permanent." I do not quite know what that means. Let me know _at your leisure_ whether it means permanent under certain conditions, and, if so, what; or merely in a general way that the pigment stands, but only pretty well. The Rosso Saturno I quite understand is to be set aside.

Another perplexity is in regard to the Burnt Madder. If the madders are in themselves sound colours, as I have always understood them to be, how do they lose their permanence by burning? I should like to use the Gialetto, and I rather gather from what you say that I may do so. I hear with interest what you tell me of your new varnish. As for myself, I have got to dislike the use of any resins in my work to such an extent that I have completely set them aside. Of course when a picture is finished it requires some gum, not only to protect it, but to bring up the colour to its full value. Will you let me know--but this will do at your leisure, for the time has not come yet--whether a picture being painted as I paint mine, exclusively with Bell's medium and turpentine from first to last, and, I may add, worked on up to the last moment of sending in, _i.e._ a fortnight later, may on the walls of the Academy be safely varnished with this new material of yours, either alone or diluted with a little poppy oil? I look forward with interest to Heyl's Madder Green.

_December 5, 1891._

I shall certainly try the Heyl's Madder Green, which I hear of through you for the first time. Laurie's daffodil cadmium is very pretty. I have got some; but my new delight now is yellow cobalt, which you have found to be absolutely safe, and which is absolutely delightful as a colour.

My tempera is come from Italy, and I am told that it is made of the tails (feelers?) of the cuttle-fish (sepia). Would you like to look at it again from curiosity? I understand that with the reservation that it darkens, I may use it with impunity in, under, and with the oil--that is enough for _my_ purpose.

_October 16, 1894._

Will you kindly advise me on the tempera, of which I send a tube? It is used by my friend, Prof. Costa, who gave it me; he likes it vastly. It coalesces _with oil_; he uses it also by itself _between_ two paintings in oil. I have often longed for something to keep down the _greasiness_ and _slipperiness_ of oil paint when correcting or going over a surface often, oil and water _do_ coalesce sufficiently. The most luminous thing I ever painted (and it has stood like a rock) was painted (or certainly _thickly under_painted) with a vehicle made of _starch and oil_.

What _this_ medium is, I don't know. Please advise.

_March 7, 1894._

Forgive secretary again.

I am much obliged by your note, and read with great satisfaction what you say about Newman's golden ochre. I shall now, until I hear from you further, adopt the motto "Ex uno disce omnes," and a.s.sume that the _yellow_ ochre is equally sound and serviceable; although the colour is so much finer than any yellow ochre of my acquaintance that I cannot quite close my mind to a lurking suspicion that it is stimulated or refreshed by some foreign ingredient.

_March 13, 1894._

Many thanks. You send me good tidings. The yellow ochre is by far the finest I have ever seen.

I enclose, because we think (Watts and I) that it will interest you, a specimen of purple _lake_ (_not madder_), such as Watts has used _all his life_, which has been baking in the sun for _two_ years; it is slightly browner, but more beautiful than ever, and has, you see, retained its full _body_; this is remarkable.