ON PREVENTING THE DECAY OF WOOD* 335 



Tbe bituminous substance melted by heat out of coal, Coal tar. 

 and commonly called coal tar, lias been strongly recom- 

 mended for this purpose by that ingenious philosopher 

 Lord Dundonald. I have tried it largely and unsuccess- 

 fully, though perhaps not fairly ; for the workman whom 

 I employed, in order to make it work more easily, added 

 to it oil of turpentine, which certainly diminished its du- 

 rability by rendering it more miscible with water. I am 

 however inclined to believe, that no substance of this kind, 

 used by itself, will become sufficiently dry and hard to resist 

 the influence of the weather. 



As animal oils are considerably cheaper than those ex- Animal oils 

 pressed from vegetables, attempts have been made to com- ma e rying ' 

 municate to them a drying quality. This has been effected 

 by dissolving in them while hot various substances capable 

 of being melted, in such a portion that the whole mass 

 would become dry and hard when cold. Bees' wax, resin, 

 and brimstone are found to have this property. Some of 

 them, when united with drying oil, have long been em- 

 ployed for making boots and shoes water-proof, or im- 

 pervious to moisture^. But they will also succeed when 

 mixed with train oil, which is obtained from the blubber of 

 the whale. In the second volume of the Memoirs of this 

 Society, printed in the year 1783, there is the following 

 receipt. " Melt twelve ounces of resin in an iron pot or Composition q* 

 kettle; add three gallons of train oil and three or four, ort ' 

 rolls of brimstone; and when the resin and brimstone are 

 melted and become thin, add as much Spanish brown, or 

 red or yellow ochre, or any colour you want, first ground 

 tine with some of the oil, as will give the whole as deep a 



* For this purpose there is the following receipt by Mr. Barker Old receipt for 

 in Sir John Hawkins's edition of that entertaining work, Isaac ^ ater -P r °o f 

 Walton's complete Angler: 4th edition, page 223. " Take a pint 

 of linseed oil, with half a pound of mutton suet, six or eight 

 ounces of bees' wax, and half a pennyworth of resin. Boil all this 

 jn a pipkin together ; so let it cool till it be milk-warm. Then take 

 a little hair-brush, and lay it on your new boots ; but it is best that 

 this stuff be laid on before the boot-maker makes the boots ; then 

 brush them once over (with it) after they come from him. As for 

 •Id boots, you must lay it on when your boots be dry." 



4 shade 



