SUBSTANCE OF MUSHROOMS. 335 



Antenrieth, a German professor, stated some time ago that 

 when wood is deprived of everything soluble, reduced to pow- 

 der, repeatedly subjected to the heat of an oven, and then 

 ground in the manner of corn, it yields, boiled with water, a 

 flour which forms a jelly like that of wheat-starch, and when 

 fermented with leaven makes a perfectly uniform and spongy 

 bread. Moreover, it is stated on the authority of Linnaeus 

 that the Laplanders eat bark-bread, prepared from the bark of 

 Pinus sylvestris, during a great part of the winter, and some- 

 times during the whole year. 



Of these facts an explanation has been offered, which may 

 or may not be sufficient to account for the whole matter. It 

 is supposed that in the autumn, after the formation of wood 

 has ceased in the vegetable kingdom, starch is formed and 

 diffused through every part of a plant by the autumnal sap. 

 It is asserted that the starch thus deposited in the body of a 

 tree can be recognised by the microscope in its well-known 

 form : again, that the barks of several aspens and pine-trees 

 contain so much of this substance that it can be extracted from 

 them, as from potatoes, by trituration with water. Thus it 

 remains to be proved whether the nutritive principle exists 

 in the wood and bark, or be the starch thus supplied by the 

 autumnal sap. 



Fungine. Closely allied to vegetable celluline is the sub- 

 stance of mushrooms. Fungine, then, is what remains after 

 mushrooms have been deprived of everything soluble in water, 

 alcohol, and a weak alkaline solution. It has been believed to 

 contain nitrogen, but some doubts have arisen on that point. 



Table of the quantity of lignine that is, of celluline 

 incrusted with ligneous substance in 100 parts of the fol- 

 lowing alimentary matters : 



