138 
All these substances were submitted to experi- 
ment green, and in their natural states. It is pro- 
bable that the excellence of the different articles, as 
food, will be found to be in a great measure propor- 
tional to the quantities of soluble or nutritive mat- 
ters they afford ; but stiJl these quantities cannot be 
regarded as absolutely denoting their value. Al- 
buminous or glutinous matters have the charac- 
ters of animal substances ; sugar is more nourish- 
ing, and extractive matter less nourishing, than 
any other principles composed of carbon, hydro- 
gene, and oxygene. Certain combinations like- 
wise of these substances may be more nutritive 
than others. 
I have been informed by Sir Joseph Banks, that 
the Derbyshire miners, in winter, prefer oat-cakes 
to wheaten bread ; finding that this kind of nou- 
rishment enables them to support their strength 
and perform their labour better. In summer, they 
say oat-cake heats them, and they then consume 
the finest wheaten bread they can procure. Even 
the skin of the kernel of oats probably has a 
nourishing power, and is rendered partly soluble 
in the stomach with the starch and gluten. In 
most countries of Europe, except Britain, and in 
Arabia, horses are fed with corn of different 
kinds, mixed with chopped straw ; and the 
chopped straw seems to act the same part as the 
husk of the oat. In the mill 14lbs. of good wheat 
yield on an average ISlbs. of flour ; the same 
quantity of barley l^lbs., and of oats only Slbs. 
In the south of Europe, hard or thin-skinned 
wheat is in higher estimation, than soft or thick- 
