Re: "serum of milk"
----- Original Message -----
From: "Liam Lawless" <lawless@bulldoghome.com>
To: <alt-photo-process-l@usask.ca>
Sent: Wednesday, June 25, 2008 10:24 AM
Subject: RE: "serum of milk"
Email trouble here means this probably won't arrive for a
week, but in case
you're still interested...
A Dictionary of Photography, Thomas Sutton, c. 1858:
SERUM of MILK. Serum, or whey, is the watery liquid which
remains after the
cream and cheese have been removed from milk. It contains
a sugar called
sugar of milk and some soluble salts, also a small
quantity of uncoagulated
casein. It is of great use in photographic printing upon
plain paper for
giving surface vigour to the proofs without any
disagreeable glazed
appearance; - and in the paper negative process it seems
to act better than
any other substance in giving density to the blacks,
probably from the
presence of the salts of lactic acid which it contains.
The simplest and best mode of making whey for the paper
processes is to add
lemon juice to skimmed milk in the proportion of about 2
spoonsful of lemon
juice to a quart of whey. Boil them together and strain
the liquid through
a cloth, which separates it from the curd. It should be
of a greenish
colour and slightly opalescent. About 6 grains of salt
may then be added
for a positive printing paper and about 5 grains of salt
and 10 of iodide of
potassium for negative paper. The acidity of the whey
thus prepared
preserves the whites of the paper beautifully.
Whey may be made by adding a piece of rennet about 3
inches square to a
quart of skimmed milk, and putting it in a bason on a hob
so as to raise the
temperature to about 120 degrees. In half an hour or so
the curd is formed.
This is called sweet whey, from its being not so acid as
the other. It
contains rather more casein.
So, it just remains to find out what a 'bason' is.
Liam
Perhaps an alternative spelling of basin.
If you have a hob you will have Sherlock Holmes coming
around to knock out his pipe on it.
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com