40 SUGAR, &C. FROM LINEN RAGS. 



Many examples occur in Chemistry in which two 

 substances only, by combining in different proportions, 

 form bodies totally distinct from each other. For in- 

 stance, the air we breathe is composed of two gases, 

 oxygen and nitrogen, in the proportion of 22 of the 

 former to 78 of the latter. But if we take the same 

 gases and reverse the proportions, combining 75 of 

 oxygen with 25 of nitrogen, we produce that powerful 

 and corrosive agent, nitrous acid or aquafortis ; other 

 proportions form nitrous gas, nitrous oxide, nitric oxide 

 and nitric acid ; all of which differ materially from 

 each other in their characteristic properties. 



With regard to the manufacture of bread from saw- 

 dust, the method used by Professor Autenrieth of Tu- 

 bingen, was as follows : — • 



In the first place, every thing that was soluble in 

 water was removed by frequent maceration and boil- 

 ing : the wood was then reduced to powder, and, after 

 being repeatedly subjected to the heat of an oven, was 

 ground in the usual manner of com. Wood thus pre- 

 pared, according to the author, acquires the smell and 

 taste of corn flour. It is, however, never quite white, 

 but always of a yellowish colour. It also agrees with 

 corn flower in this respect, that it does not ferment 

 without the addition of leaven, and in this case sour 

 leaven of corn flour is found to answer best. With 

 this it makes a perfectly uniform and spongy bread ; 

 and when it is thoroughly baked, and has much crust, 

 it has a much better taste of bread than what, in times 

 of scarcity, is prepared from the bran and husks of 

 com. Wood flour also boiled in water, forms a thick, 

 tough, trembling jelly, hke that of wheat starch, and 

 is highly nutritious. 



These are some of the advantages which are derived 

 from the pursuit of chemistry ; many others might be 

 adduced, but it is presumed these are sufficient to show 

 the utility of trying experiments, 



J. N. Hearder. 



Printed and Published by G, Hearder, Buckwell Street, Plymouth. 



