296 
Milk. 
pans, they take up more room than square or oblong vessels. 
Tliev are, of course, very brittle, and liable to be broken, and on 
this account more expensive in the long run than cisterns made 
of lead or tinned iron. Glazed earthenware pans, 20 to 22 inches 
across at top, and 3 J to 4 inches deep, and 1 foot to 14 inches 
wide at bottom, are very commonly used in England. They 
should be well glazed, in order that the milk mav not penetrate 
the porous earthenware. Unglazed pans or wooden dishes are 
decidedly objectionable. Porous materials are generally objec- 
tionable for dairy use. Vessels cut out of stone are more porous 
and more difficult to keep clean and sweet than glass pans or tin 
A essels ; and many limestones are quite unfit for this purpose. A 
better material is slate, provided the vessel is cut out of the solid 
block. If it be made by joining together several slabs of slate, it 
will prove, perhaps, the worst description of milk-vessel that has 
ever been constructed. The difficulty of thoroughly removing all 
traces of the old milk which penetrates the joints of the slabs, or 
is absorbed by the cement with which the slabs are joined to- 
gether, accounts for the milk not keeping sweet in them. Zinc 
pans are said to throw up more cream than pans made of any 
other material. Zinc, however, is readily oxydised, and in an 
oxydised state easily attacked by milk. As the i:inc salts thus 
formed are decidedly injurious to health, and, moreover, zinc 
pans are difficult to keep untarnished, this material ought not to 
be used for milk-pans. Brass and tinned-copper pans, when kept 
exceedingly clean, are unobjectionable ; but as they are too 
expensive, and in the hands of careless dairy-maids may poison 
the milk, it is on the whole better not to employ them. 
Probably the greatest quantity of milk in this country is set for 
cream in leaden cisterns about 4 or 5 inches deep ; yet tinned- 
iron cisterns are on the whole preferable, as being more easily 
kept clean. It is a great mistake to put up the milk in cisterns 
4 or 5 inches deep. Such deep vessels economise space, and 
cost less than a number of small pans requiring to be rencswed 
from time to time ; but what is gained on the one hand is lost 
on the other, by the smaller (juantity and the inferior quality 
of the cream which they give, in comparison with shallow 
vessels. 
The cpiicker cream can be made to rise the better its quality ; 
for cream, like all perishable substances, does not preserve its 
original properties for any great length of time. The cream, or 
rather milk-globules, being lighter than the fluid portion of milk, 
necessarily rise in a shorter time from a less depth than from a 
greater depth, because they have less pressure to overcome than 
those in the deeper strata ; the action is also more complete, as 
