STUCCO FO^ PHESERTING STONE. ]1 



superintendant of the royal buildings to try a preservative prevented by a 

 stucco. Accordingly three pillars in the court of the Lou- '^"""P°^^'^'®"» 

 vre were coated with this stucco for half their length, two' 

 facing the south, the other the west. These were still re- 

 markable in July last for the uniformity of their tint, strongly 

 distinguished from the dull gray and earthy aspect of the 

 contiguous parts: but as the alterations made in com- 

 pleting the Louvre would necessarily destroy every trace of 

 this experiment, the Institute appointed o committee to 

 inquire concerning it, before it should be too late. 



In company with Mr. Fontaine, architect of the Louvre, too thin to In- 

 the gentlemen abovementioned examined the pillars, and s"uL\u^e '^^^^ 

 found, that the stucco applied formed a coat too thin to 

 injure the finishing of the most delicate sculpture ; that it 



retained a uniform colour even in the parts exposed to the ^"'^ unaffected 



- , . -, . , , , , . . . 1 , by the wea- 



action or the wmd, ram, and sun; that rubbing it with the nicr. 



hand made no impression on it; and that, if one of the 



three pillars exhibited a reddish yellow tint, there could be 



no doubt, from its appearance in other respects, that this 



was owing to some colouring matter added intentionall3\ 



It could not be found on inquiry, that Mr. Bachelier Account of it 

 had consigned his process to writing, and the following was ^^o^J "^.^'"O'^y 

 the best account his son could give of it from memory, ventor'sson. 

 ♦' Its basis consists of the sifted powder of oystershells, pre- 

 viously washed and calcined to whiteness, mixed with the 

 butyraceous and caseous part of milk. My father used the 

 common cheese known by the name o? Jromage a la pie 

 [skimmed milk cheese?]. He firstseparated all thewheyey 

 part by pressure, and then left it fome time exposed to the 

 air to dissolve or soften. In this state he mixed with it a 

 q[uantity of calcined oystershells in fine powder. When 

 \h\s mixture was brayed on a stone, the cheese softened, 

 *nd formed a very smooth and whitish liquid paste. To 

 nake the stucco he diluted this with a solution of alum in 

 vater; the quantity of water being proportioned according 

 b the thickness of the coat intended to be applied." 



Mr. Bachelier could say nothing of the proportions of Paper coated 

 tie ingredients, he only added, that, his father leaving ;;;i;^j;^7j^^ 

 tjought of employing this composition undiluted to cover could beef. 

 ^aves of pap^r> from which writing was easily effaced by a ^^^^'^' 



wet 



