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.
Many thanks for your valuable note. I may say in passing 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.
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.
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.