ON AMBER VARNISH. A3fDA?:iP. 229 



hope of collecting any after the oil of turpenti'.e is added, 

 as this oil, p-irtly converted into vapour by the heat of the 

 mixture, so as to make it swell up or even boil over, occa- 

 sions the acid to disappear entirely. 



However miniite the means I have employed for collect- Method of do* 

 ing the succiuic scid may appear, I think it indispensable*"^ ^'*' 

 to describe them. At first I thought of taking it off witli 

 a card. This answered pretty well, but there is danger of 

 burning tlie fingers, if from inattention they should touch 

 the keated matver. I found a mvich more convenient in- Instrument do 

 strutnent was a tin spoon, made as represented in PL VI, ^*^'^^"*^' 

 where fig. 4 is a side view of it, and fig. 5 a front view. - 

 Tliis spoon differs from others only in the form of its bowl, 

 which4s but little concave, the front of it forming a seg- 

 ment of a circle, and adapted to the size of the matrass ; 

 which is represented at fig. 6, but on a much smaller scale, 

 not to occupy too much room in the plate. The bowi of 

 the spoon is terminated behind by a thin plate of iron, 

 which rising a few lines above its edges foi'ms a sort of neck, 

 and to this is joined a handle of the same material, sixteea 

 inches long, forming a right angle with the bowl. The 

 shape of this spoon appeared to me the most convenient, be- 

 cause, 1st, as it adopts itself accurately to the sides of the 

 vessel, it prevents the sublimed acid, which is scraped off 

 by drawing up the spoon, from mixing with the melted am- 

 ber : and 2d!y, it allows the operator to collect it without be- 

 ing incommoded by the vapours emitted. 



From what has been said it appears, that artists em- Varniih makers 

 ployed in making amber varnish, without any alteration in ^^y.^*^"^^^ * 

 their usual processes or apparatus, may furnish us in future quantity of the 

 with a pretty large quantity of succinic acid, which has *^^^' 

 hitherto been confined to medical uses, but may soon be 

 found beneficial in other arts. Some trials already give Useful for 5 mi- 

 me room to hope, that its solution in alcohol may be em- L*""^ ^'^f^ 

 ployed to imitate the colour of some valuable woods. 



XV. 



