lo8 On a New Species oj Manna from New SuulJi Wales. 



so that I was under the necessity of abandoning this process, 

 and determining it by difference. This was effected in the 

 following manner: — The residue, after extraction by alcohol 

 and cold water, and which, of course, contained the starch, 

 inulin, and cellulose, was weighed, and then boiled with 

 water. The insoluble residue of this process, which was 

 cellulose, was washed, dried, and weighed ; the inulin which 

 deposited from the boiling solution on cooling, was likewise 

 washed, dried, tind weighed. Tiie difference between the sum 

 of these weights, and that of the whole original residue, was 

 reckoned as starch. This method, which was the best the 

 circumstances admitted of, is not one of very high accuracy ; 

 but I believe it to approximate pretty closely to the truth. 

 I think it likely, however, that the starch is rather under, 

 and the inulin overrated, as, owing to the slight solubility 

 of the latter substance, it was impossible to carry the 

 washing very far. The following are the results I ob- 

 tained : — ■ 



Such being the constitution of this curious substance, the 

 question of its origin becomes of very great difficulty. All 

 the species of manna regarding which we have explicit in- 

 formation appear to be exudations consequent upon the punc- 

 ture of an insect, and they are composed of substances en- 

 tirely soluble in water, which may easily be conceived to ex- 

 ude in solution, and gradually dry up in the rays of the sun, 

 as indeed is actually the case with common commercial 

 manna. But in this manna, we have present the insoluble 

 cellulose, wit!: starch, which is absolutely insoluble, and inu- 

 lin, whicli is sparingly soluble in cold water ; and it is very 

 difficult, under any circumstances, to suppose that these sub- 



