PROCESS FOR DETECTION OF ADULTERATIONS. 95 
to possess health ; or 950 cubic feet of air are necessary for 
the natural respiration of the animal to be carried on. 
But this calculation supposes that the whole of the oxygen 
taken into the lungs is changed into carbonic acid gas ; which 
is not the case, it being only about one third — the expired 
air from the horse containing between 6 and 7 per cent . 
carbonic acid — consequently three times that bulk of air, or 
2850 feet are required for a horse per diem. How plainly 
does this show the necessity of proper ventilation being 
allowed where this animal is confined ! And this, too, w ithout 
taking into account the further necessity arising from the 
excretions and secretions, which are constantly going on, 
and by which the air is also rendered impure. 
Extracts from British and Foreign Journals. 
ON A PROCESS FOR THE DETECTION OF CERTAIN 
ADULTERATIONS OF OIL-CAKE, FLOUR, AND BREAD. 
By Thornton J. Herapath, Bristol. 
From the statements that have been made in the Agri- 
cultural Gazette and other periodicals, it would appear, that 
the rape and linseed cakes, which are now so much used for 
feeding cattle, are often purposely adulterated, by unprin- 
cipled manufacturers, with mustard cake ; and even the less 
costly varieties of oil-cake, w 7 hich are employed in this 
country as manures, are said to be sometimes sophisticated 
with cheaper materials. 
Having been called upon lately to examine several speci- 
mens of rape cake, which were supposed to be largely 
adulterated with mustard, I long experienced considerable 
difficulty in detecting the presence of the latter, as 1 found 
that the results afforded by the ordinary method of analysis 
were not in every instance perfectly satisfactory. The usual 
mode of examination, it is well known, consists in reducing 
the cake to a fine powder, and mixing it with cold w 7 ater, 
when the presence of mustard is supposed to be evinced by 
