377 
of simple alimentary substances , &c. 
by subjecting it to higher temperatures. Thus, after having 
been exposed a ■ above for 24 hours to the temperature of 
212 0 , on being further submitted to a temperature between 
300° and 350° for six hours longer, it lost 2*3 per cent, more, 
and analysed in this state gave ' ery nearly 
Carbon 44 
Water 5?. 
It had now acquired a slight yellow colour, and seemed to 
have suffered some change in its properties ; hence, this is 
probably nearly the utmost quantity of water that starch is 
capable of parting with, short of decomposition. 
Arrow root. This is another variety of the amylaceous 
principle, of which, like sugar, there seems to be a great 
variety. The specimen on which the following experiments 
was made was remarkably fine, and free from adventitious 
matters. It had been kept in the same drawer with the starch 
before mentioned, and under precisely similar circumstances 
of the atmosphere was found to consist of ( abstracting foreign 
matters ) 
Carbon 36 ’ 4 
Water 63-6. 
One hundred parts, in the above state, exposed for twenty 
hours to a temperature between 200° and 212 0 , lost fifteen 
parts. Hence its composition, when thus dried, was very 
nearly the same as that of wheat starch similarly exsiccated ; 
or it consisted of 
Carbon 42^8 
Water 57-2. 
On being subjected to the full temperature of 212 0 for six 
hours longer it lost 3-2 per cent, more and was then reduced 
3 C 
MDCCCXXVII. 
