SCIENTIFIC SUMMARY. 
215 
at any change of .temperature, enabling the man to keep bis kiln at the 
proper beat, which is very important in malt-kilns. These pyrometers are 
used by the Government departments for baking bread ; they are also used 
for indicating the waste heat in flues of works and locomotives, for indicat- 
ing the temperature of blast-furnaces, gas retorts, and other useful purposes 
where high temperatures are used. 
Winstanley* s Coal-cutting Machine . — Certainly mechanical invention seems 
to rapidly do away with the necessity for multitudes in the shape of hand 
labour. This machine is designed for holing in mines which are worked on 
the wide work or long wall system. It is driven by compressed air, the 
pressure required being from 20 to 30 lbs. per square inch, according to the 
nature of the coal, to be cut. The height of the machine is 22 in., and 
the gauge of the wheels can be made to suit any ordinary colliery tramway. 
The cutter holes its own way into the coal, cutting from nothing up to 3 ft. 
or more in depth, the thickness of the groove being 3 inches. The small 
coal made by holing represents only from 25 to 35 per cent, of the 
quantity of small coal produced by hand holing. The average rate of holing 
in hard coal, with a pressure of 30 lbs. per square inch, is 25 yards per 
hour, including stoppages, and this may be considered to equal the work 
which would be done by at least thirty men in the same time. See 11 Re- 
port of the Manchester Society for the Promotion of Scientific Industry.” 
MEDICAL SCIENCE. 
The way in xohich the Body uses up its Food . — A paper by Herren Petten- 
kofer and Voit, which originally appeared in the “ Zeitschrift fur Biologie,” 
Band ix., Heft 1., is of some interest. The present paper deals only with the 
processes of disintegration which occur in the body when varying proportions 
of meat and fat are given as food. In some of these 1,500 grammes of meat 
were given with 30, 60, 100, and 150 grammes of fat ; in others 500 grammes 
of meat with 200 of fat ; and so on. Their experiments showed that fat is 
absorbed in large quantities from the intestine, and that within certain 
limits the larger the quantity of fat in the food the more is absorbed. But 
when a certain proportion has been stored up in the body, less is taken up 
from the intestine. The most important conclusion at which they have 
arrived is that albumen is, under ordinary circumstances, more easily split 
up in the body into simple products than fat, so that so far from fat retarding 
the disintegration of albumen, albumen, if taken in sufficient quantity by a 
carnivorous animal, delays the oxidation of the fat, by splitting up into 
some form of oleaginous compound and other secondary products, the former 
of which is more easily oxidizable than ordinary fat. The fat derived from 
the albumen must of course be estimated as food fat, and viewing it in this 
light, it may be said that the consumption of fat in the body increases with 
the amount of albumen present in the body, or in other words, the better 
the general state of the nutrition of the body, the more fat is disintegrated. 
Lastly, they show that the disintegration of fat increases notably with 
physical exertion. 
