38 
Composition of Cheese. 
The two Stilton cheeses are very rich in butter, especially the 
second, which contains 44 per cent, of pure fatty matters ; and 
as we have in common butter from 15 to 18 per cent, of water, 
besides casein and other impurities, the 'pure fat in the second 
Stilton represents more than 50 per cent, of butter. The first 
analysis expresses tlie composition of a rather new Stilton. It 
was sold at Is. per lb. last October. The second analysis is that 
of an old Stilton, sellinjj at \Ad. per lb. There is about 12 per 
cent, less water in it than in new Stilton ; more butter and less 
salt. Notwithstandino; the smaller amount of salt, it had a more 
saline taste and much better flavour than the newer cheese. 
This saline taste is sjenerally ascribed to the salt, and complaints 
are sometimes made by persons fond of mild-tasting; cheese, that 
old cheese, in other respects rich and goodj has been injured by 
too much salt. This is a mistake, of which the proof is found 
in the analyses of these two Stilton cheeses. The first was (juite 
mild in flavour in comparison Avith the other, and yet it contained 
three times as much salt as the more saline-tastinf; older cheese. 
The fact is, the saline taste is developed during the ripening of 
cheese ; newly-made cheese, though strongly salted, is always 
mild in taste. During the ripening of the cheese a portion of 
the casein or curd suffers decomposition, and is partially changed 
into ammonia ; the latter, however, does not escape, but com- 
bines with several fatty acids formed in the course of time 
from the butter. Peculiar ammoniacal salts are thus produced, 
and these, like most other salts of ammonia, have a pungent 
saline taste. The longer cheese is kept, within reasonable limits, 
the riper it gets ; and as it ripens the proportion of ammoniacal 
salts, with their pungent saline taste, increases. It can be 
readily shown that old cheese contains a good deal of ammonia 
in the shape of ammoniacal salts. All that is necessary is to 
pound a piece with some quick-lime, when, on the addition 
of a little water, a strong smell of spirits of hartshorn will be 
developed. In well-kept, sound old cheese the ammonia is not 
free, but exists in the form of salts, in which the base is ammonia 
in combination with butyric, caprinic, caprylic, and other acids, 
generated under favourable circumstances by the fats of which 
butter consists. Ripe cheese, even if very old, but sound, in- 
stead of containing free ammonia, always exhibits a decidedly 
acid reaction when tested with blue litmus-paper. Rotten cheese, 
on the other hand, is generally alkaline in its reaction, and 
contains free ammonia. 
I have made a quantitative determination of the amount of 
ammonia in old Stilton cheese, and found it to amount to 1"81 
per cent. 
The first Cotherstone or Yorlcshire Stilton was made near 
