472 Steam Engines. 
All these substances were submitted to experiment green, and 
in their natural states. It is probable that the excellence of the 
different articles as food will be found to be in a great measure 
proportional to the quantities of soluble or nutritive matters they 
afford ; but still these quantities cannot be regarded as absolutely^ 
denoting their value. Albuminous or glutinous matters have the 
characters of animal substances; sugar is more nourishing,* and 
extractive matter less nourishing, than any other principles com« 
posed of carbon, hydrogen, and oxygen. Certain combina-* 
tions likewise of these substances may be more nutritive tlian 
Others. 
I have been informed by Sir Joseph Banks, that the Derby-* 
Shire miners in winter, prefer oat cakes to wheaten bread ; find- 
ing that this kind of nourishment enables them to support their 
strength and perform their labour better. In summer, tliey say 
Oat cake heats them, and they then consume the finest wheaten 
bread they can procure. Even the skin of the keniel of oats pro- 
bably has a nourishing power, and is rendered partly soluble in 
the stomach with the starch and gluten. In most countries of 
ilurope, except Britain, and in Arabia, horses are fed with barley 
mixed with chopped straw ; and the chopped straw seems to act 
the same part as the husk of the oat. In the mill 1 4lbs. of good 
wheat yield on an average 13lbs. of flour; the same quantity of 
barley 12lbs. and of oats only 8lbs. 
In the south of Europe, hard or thin-skinned wheat is in high- 
er estimation, than soft or thick-skinned wheat: the reason of 
which is obvious, from the larger quantity of gluten and nutritive 
matter it contains. I have made an analysis of only one specimen 
of thin-skinned wheat, so that other specimens may possibly con- 
tain more nutritive matter than that in the table. 
STEAM ENGINES. 
SINCE concluding this article, a few pages back, new commu- 
nications induce me to resume it. 
I have already mentioned, that on a rail-way near Leeds in York- 
«^hire, in England, a waggon containing a steam-engine, drags after 
* This may be : so thought Cufisn : but I know of i\o experiments tcj 
prove tlii?, T. C. 
