216 LICHENS A3 FOOD. 



residue. Lichen^ boiled and dried, affords no more than 21 

 or 22 hundredth parts of coal. 



The nitric acid dissolves the boiled lichen with great faci- 

 lity ; an effect wiiich is not commonly seen with the ligneous 

 vegetables. The product is oxalic acid and oxalate of litoe, 

 augmented, as seemed to the professor, by a foreign earth. The 

 residue contains the yellow bitter principle in a very small 

 quantity. 

 Habitude with Potash converts boiled lichen into a gelatinous pulp, similar 

 ^ ' to that which is afforded by farina in like circumstances. These 



facts appear to show, that the fleshy part of this plant is an 

 indurated gum, less oxigenated perhaps than those which are 

 soluble. The jelly of lichen may be used as food. The 

 Blanc monge, author made a very good blanc-manger, by adding a small 

 ^^* quantity of flour, with sugar, and afterwards some milk, or 



emulsion of almonds. The author here makes a remark con- 

 cerning the necessity of condiments or seasoning, to give 

 flavour to this jelly ; and takes notice, that the same necessity 

 exists with regard to all gelatinous foods, whether animal or 

 vegetable. Starch, as he remarks, is the basis of bread, and 

 glue of soup ; neither of which would be acceptable to the 

 palate, or supportable by the stomach, without some stimu- 

 Whether the lating ingredients to season them. The analogy of lichen to 



^"'^"jy 2*^ j^'^ starch, in its want of solubility in cold water, is opposed by 

 would afford , , . „ , . , , , • ■, i • i i i , 



starch by fer- the citfference, that it has no adhesion yvhen dissolved ; but he 



mentation. thinks it would be interesting to treat the lichen by an appro- 

 priate fermentation, to see whether (his ferment would not 

 sepaiate it like starch. He likewise suggests the probable ad- 

 vantages to be derived from an examination of the several spe- 

 cies of the vast family of the lichens. 



XI. On 



