at Home and Abroad. 
131 
without injury, for an indefinite time. But in France, as in all northern 
countries, the ensila2;e of the grain has not succeeded, and this is attributed 
to the humidity of the soil, which penetrates to the interior of even the best 
constructed silos. Then it has been observed that corn properly ventilated 
is less subject to become heated in the granaries than that left alone. It was 
believed that the problem had been solved by the airing and ventilation of 
the grain. Moving granaries and granaries with ventilators were suggested, 
but they are all extremely expensive, and they do not safely prevent fer- 
mentation. They also put no obstacle to the development of insects. The 
success that has been obtained by using these means appears to be simply due 
to the dryness of the wheat. But, as Doyeee has asserted, dry grain can be 
preserved for a certain time by any means. But it is not the same with wet 
grain, that is to say, grain containing more than 16 per cent, of water, like 
the greater part of French corn does. " I found," says Doyere, " that corn 
containing 21 per cent, of water furnishes, at 68° Fahr. (20° Centigrade), 
120 milligrammes of carbonic acid per day and per kilogramme (about 2j lbs. 
English) in a state of rest ; and about 17 milligrammes per hour under the 
influence of a constant current of air, which latter amount would make 
408 milligrammes per day. Ventilation therefore trebles the amount of 
decomposition, of which carbonic acid is one of the products. The last of 
these losses is enormous, for it represents not less than 2i per cent, of dry 
matter destroyed each month, owing to alcoholic fermentation. It is pro- 
bable that it would not be continued indefinitely to the same extent as it 
happens for several hours ; but it is renewed with the same energy during 
the whole time of an intermittent ventilation. Otherwise, the loss of 120 
milligrammes of carbonic acid per day, which hardly requires any renewal of 
air, suffices to repel the hope of a preset ation of long duration, for it repre- 
sents a destruction of dry matter amounting to 7 per 1000 per month. This 
is not only the loss in weight, for the loss in quality which results from the 
formation of sour and rank products is incomparably more to be feared. 
Finally, as the loss takes place in a temperature relatively low, that of 
68° Fahr., it would not only increase with the temperature, but eveja 
much more rapidly. Therefore vrhen the grain is wet, the airing produces 
an effect very much opposed to that which is commonly looked for." The 
results of the experiences of Doyere show that, in the grain containing less 
than 16 per cent, of water, there is only produced an alcoholic fermentation, 
excessively weak, without developing odour or taste, and only to be perceived 
by the most delicate processes of chemistry. 
In other cases, even this fermentation is stopped in closed vessels. After 
the oxygen of the air, which is its primitive cause, has completely disappeared, 
no other acid but carbonic acid is formed ; the starch and gluten undergo no 
change. Towards 16 per cent, of humidity, or a little beyond it, the altera- 
tion in the grain begins to show itself, in the course of time, in the closed 
vessels. Its relative activity in corn of various degrees of humidity increases 
with the proportion of water, but much more rapidly than the humidity 
itself. It is due to fermentation, called by the chemists lactic, butyric, and 
gaseous. Consequently, whatever may be the means employed, it is im- 
possible to preserve grain wet, as it generally is in France. The excessive 
humidity of corn in our country ought not, however, to be attributed only to 
the climate and climatic influences in which the grain has been harvested. 
Agricultural customs have much to do with it. In the greater part of France 
the wheat is cut half green, and is hastily put into the granary or made into 
1^ ricks, where it immediately begins to ferment. If, as we think, the observa- 
tions of Doyere are correct, it is evident that the corn intended to be pre- 
served must be dried in the first instance, if it coutaius 16 per cent, of 
humidity or more. As to the place where it is best to keep it, the silo appears 
H 2 
