Robersons, when they came to roll up my fresco to transport it to the Exchange, found that either the ground or the pigment--probably both, as they are of the same substance--was extremely brittle and cracked right across, cracking at a rather abrupt tangent from the circumference of the circle; so that they immediately struck work, and declined to go any further. As far as the painting itself is concerned, I do not believe that any serious damage is done, because on re-straining it flat, the cracks are barely perceptible, and probably would not be at all perceptible in _situ_. Meanwhile, if any question arises as to the ground, it has occurred to me, and it is on this point I wish to consult you, that the cause may be the substitution of paraffin wax for the ordinary wax hitherto used in Gambier Parry's material, which, though perhaps not absolutely so durable as paraffin, is sufficiently so, and very malleable. One does not see what else could have cracked in that abrupt and sharp manner--certainly not the copal, which has oil in it and is further made supple by the oil of spike. If it turned out that the paraffin was the peccant element, I should be, _entre nous_, rather glad, because it diminished the facility of the work. * * * * * With reference to the cracking of this work Professor Church writes:-- This unrolling was begun in very cold weather; if the temperature had been a little higher, nothing of this kind would have taken place. The picture now shows no sign of defect or injury, and is in perfect condition. By substituting _ceresin_, a paraffin obtained from ozokerite or earthwax, for crystalline paraffin, the chance of cracking is obviated. The ceresin, which should have a melting-point of 150° or 160° Fahrenheit, constitutes a safe substitute for the beeswax commonly employed in Gambier Parry's Spirit Fresco Medium. FOGGIA, _October 15, 1895_. You will be surprised to get a letter from me with an Italian superscription; I am writing thus early before my return to save time. When I was in Venice the other day, Van Haanen spoke to me, _with approval_, of a certain vehicle, of which I had already heard before vaguely, the invention of the French painter, Vibert. You probably know of it, as the subject of media has occupied you. There are, it appears, three forms of this medium: the vehicle for painting, the medium for painting _into_ in retouching, and the final _varnish_. As far as I understood Van Haanen in a hurried conversation--he was a little vague--the painting medium contains no gum, only, he seemed to think, petroleum and oil; I assume that in the final "vernis" there _is_ gum of some kind.