DOI Page / Citation link:
https://doi.org/10.11588/diglit.19571#0076
& THE ARTIST'S ASSISTANT.
ration called parting. Yerditer is to be had at a
cheap rate from the refiners, who are at no expence
in making it, but that of the chalk and labour. The
manner in which it may be beft done by them is as
follows :
'; Take any quantity of chalk, and having ren-
H deredit fufficientlv finebv wafhins over carefully,
i: add it gradually to the folution of copper, lo long
" as anv change appears to be produced by it from the
w ebullition excited ; or the due proportion may be
" perceived by the fluid lofmg its green tinge and
" becoming colourlefs. Let it then ftand at reft
" till the iediment be fubfided, and pour off the
"clear part of the fluid from the powder; adding
" in its place clean water, which muft be feveral
*' times renewed till the falts be entirely wafhed
e: cut. The iediment, which is the verditer, muft
t£ be afterwards freed from the fluid by filtering
" through paper covered with a cloth, and laid out
<; in lumps of a middling fize to dry."
Thofe who defire to make verditer themfelves,
may prepare the folution of copper, by adding cop-
per hiings gradually to aquafortis of any kind, or
putting plates of copper in it; and then proceeding
as is above directed for the refiners folution.
BLEU Jc CENDRES; or SANDERS BLUE.
If enquiry is made at the colour fhops for this
article, nothing is to be found under the name but
common verditer, or a fpecies of it where the pre-
cipitation of the copper appears to be made in part
upon ftarch as well as chalk. It may be prepared as
follows :
<; Take
ration called parting. Yerditer is to be had at a
cheap rate from the refiners, who are at no expence
in making it, but that of the chalk and labour. The
manner in which it may be beft done by them is as
follows :
'; Take any quantity of chalk, and having ren-
H deredit fufficientlv finebv wafhins over carefully,
i: add it gradually to the folution of copper, lo long
" as anv change appears to be produced by it from the
w ebullition excited ; or the due proportion may be
" perceived by the fluid lofmg its green tinge and
" becoming colourlefs. Let it then ftand at reft
" till the iediment be fubfided, and pour off the
"clear part of the fluid from the powder; adding
" in its place clean water, which muft be feveral
*' times renewed till the falts be entirely wafhed
e: cut. The iediment, which is the verditer, muft
t£ be afterwards freed from the fluid by filtering
" through paper covered with a cloth, and laid out
<; in lumps of a middling fize to dry."
Thofe who defire to make verditer themfelves,
may prepare the folution of copper, by adding cop-
per hiings gradually to aquafortis of any kind, or
putting plates of copper in it; and then proceeding
as is above directed for the refiners folution.
BLEU Jc CENDRES; or SANDERS BLUE.
If enquiry is made at the colour fhops for this
article, nothing is to be found under the name but
common verditer, or a fpecies of it where the pre-
cipitation of the copper appears to be made in part
upon ftarch as well as chalk. It may be prepared as
follows :
<; Take