THE CARE OF PICTURES AND PRINTS. 95 



there is not a hiatus like an empty space which is inclosed within the 

 four sides of a picture. The only excej)tions to the necessity for res- 

 toration in damaged pictures are those cases in which a fragment of 

 ancient painting is preserved less as a work of art than as an object of 

 antiquarian interest. Then, of course, however mutilated, it must re- 

 main in its mutilated condition like all those things which are valuable 

 as materials for antiquarian studies. 



Vermin have to be guarded against carefully in the preservation of 

 works of art. Drawings and engravings are generally protected either 

 by portfolios or by glass, which prevent the droppings of flies from 

 spotting them ; but I have seen prints spoiled in this way by being 

 carelessly left upon a table for a very short time, when the flies took 

 their opportunity and left their black dots. Their excrement is sol- 

 uble in water, and can be removed easily from any hard substance 

 while it is fresh, though it hardens and becomes less soluble after- 

 ward ; but on an engraving it is disastrous, as it sinks into the paper 

 like a stain. It therefore becomes a necessary precaution, especially 

 in summer, to cover a print that is left on a table, or, better still, never 

 to leave prints on tables at all. 



The worms that bore into wood are dangerous only to pictures on 

 panels, and, as very few pictures are painted upon wood in these days, 

 this enemy is not so much to be feared. When he attacks an old panel 

 his holes may be stopped with a little marine glue, applied hot ; but it 

 is curious how often worms will attack a thin piece of wood without 

 penetrating to the other side. In two specimens before me, small 

 panels three eighths of an inch thick, and about four inches by five, I 

 find that in one case the worms have made twenty-two holes, not one 

 of which has got through to the other side : and in the other case there 

 are twenty-five holes, of which only seven have as yet penetrated. 



The only way to keep prints and drawings from the attacks of rats 

 and mice is to have them always in closed cases if they are not framed, 

 and, if the cases are of wood, it is a good precaution to have them cov- 

 ered with thin sheet-iron behind and beneath, while the front panels 

 may be glazed. Tin boxes are a perfect protection against rodents, 

 and so, of course, is glass. Common portfolios are a poor protection, 

 as a rat willingly attacks them, and soon eats his way through to the 

 prints ; in fact, common portfolios are in all ways unsafe, being of use 

 only to keep order. The danger from rats and mice is always present, 

 for even in places where they are unknown they may at any time sud- 

 denly make their appearance. A rat may find his way into your best 

 protected room. I remember one summer's day in broad daylight, 

 too seeing a large rat quietly descending into my study by means of 

 a window-curtain, the window having been left open. He had walked 

 along a little stone ledge that the architect had carried round the house 

 as an ornament, which is a great convenience to rats. When a house 

 is perfectly quiet at night a rat will wander about in the coolest man- 



