PREPARATION OF CHARCOAL BY STEAM. 281 
distillation of wood, is easily condensed, together with 
many of these latter, which, differing in their nature with 
the stage of the operation, probably admit of being in some 
measure collected apart, and more easily isolated than when 
the whole are mixed up together. These products would 
admit of being, to a certain extent, regulated by the tempe- 
rature applied, which is susceptible of perfect coutrol. The 
manufacture of acetic acid and wood-spirit might thus be 
disembarrassed from many of the difficulties which now 
attend it. 
Bread and biscuit may be baked with the most perfect 
success by exposure for a very moderate time to a current 
of steam heated to 480° Fahr. The loaves so produced 
are particularly sweet and well-tasted, and their exposed 
parts covered with a gold-colored crust very pleasing to the 
eye. The biscuits, by proper management, are not only well- 
baked, but thoroughly dried, which in the preparation of bis- 
cuit for sea stores is a point of great importance. Strange 
as it may at first appear, steam, in the state spoken of, is a 
most powerful desiccating agent, inasmuch as it has a high 
temperature and a condition very far removed from its con- 
densing point. Into such an atmosphere water will evapo- 
rate with the greatest facility, since the elastic force of the 
vapor present is very much less than that which would be 
possessed by steam of the maximum tension and density 
proper to the temperature. High-pressure steam has already 
been employed to heat baking-ovens, having been made to 
circulate around them within an outer envelope. To gain 
the necessary temperature, however, steam of great elastic 
force must be used, the employment of which is always in- 
convenient and often dangerous. These evils are entirely 
avoided, and the process itself facilitated by the use of a 
current of heated and rarified steam within the oven. 
The desiccating powers of moderately heated dry steam 
might be applied to the rapid seasoning of deal and hard- 
wood, with perhaps less injury than the heated air of a 
24* 
