198 Notice of some Recent [March 



rotation to the right. The authors propose to retain for it 

 the term dextrine, or gum dextrine. 



The fibrous parts of fecula are kept together by interposed 

 amidone, and various bodies adhere to this envelope, as 

 carbonate and phosphate of lime, silica, and essential oil. 

 If the temperature of the fecula is gently raised in water to 

 202° the amidone swells and ruptures the envelope, pro- 

 ducing starch. 



The authors conclude with some important deductions 

 from their experiments. In laboratories, and in rural 

 economy, they suggest that diatase will be useful for the 

 analysis of fecula, flour, bread, and different amylaceous 

 substances, but more particularly, will be found an elegant 

 method of analysing organic substances. The same sub- 

 stance presents us with the means of obtaining the dextrine 

 and fibrous matter free from amidone; of procuring the 

 latter substance in abundance, and of converting it into 

 gum and sugar. M. Serres has employed dextrine in the 

 great hospitals at Paris, as a substitute for gum-arabic, 

 with success, as it is destitute of the insipid taste of that 

 substance, 



M. Guerin Varry has obtained very different results from 

 his analysis of starch, which by no means hold out to us the 

 same prospects, but, as great care seems to have been em- 

 ployed on both sides, we do not hesitate to give place to the 

 experiments of each, as we consider the subject still clouded 

 with a few ambiguities. 



We confess, however, that Varry's reasons for considering 

 the substances which he describes as distinct, are far from 

 being conclusive. 



Amidine* forms, according to M. Guerin Varry, one of 

 the constituents of starch. The method of obtaining it is 

 to boil, for a quarter of an hour, one part of the fecula of 

 potatoes in 100 parts of water, pour the liquid into a deep 

 vessel, allow it to stand till the tegumentary matter is 

 deposited, decant the fluid, filter it, and evaporate it by slow 

 boiling, to the consistence of a syrup. The residue is then 

 to be thrown on a linen cloth, which retains the amidine, 

 and allows a liquid to pass, which on evaporation at a 

 temperature below 212°, still deposits amidine. To separate 



* Ann. de Chim. ch. de phys. lvi. 225. 



