190 Miscellaneous Intelligence, 



being pressed between filtering paper, was found to dry with great 

 facility. This was then decomposed by excess of sulphuric acid, 

 and the mixed precipitate of sulphate of baryta and pectic acid 

 boiled with caustic soda by filtration, the pectate of soda was 

 separated ; and being precipitated by excess of muriatic acid, the 

 pectic acid was washed, dried, and obtained perfectly white and 

 pure. " 



A process for the preparation of larger quantities is as follows ; 

 and not requiring copious washings with pure water, may be car- 

 ried on out of the laboratory. A yellow variety of Flanders carrot 

 was rasped, pressed, and washed with common water, until the 

 latter passed off limpid. Every 100 parts of the pressed car- 

 rot, with 5 parts of bi-carbonate of potash, were boiled in water 

 the usual time, to form a clear fluid, and then pressed ; a strong 

 solution of pectate of potash was thus obtained, which, being de- 

 composed by excess of muriate of lime, gave an insoluble pectate 

 of lime. This was washed and treated with water acidulated by 

 muriatic acid ; and finally, with pure water. The pectic acid thus 

 obtained was very pure, and far whiter than that procured by the 

 use of caustic alkali. 



If a very economic process be required, carbonate of soda may 

 be used in place of bi-carbonate of potash — adding only a small 

 proportion for the first decoction (about 5 percent, of the crystals); 

 very white pectic acid will be obtained. To obtain the whole 

 quantity present, new decoctions, with fresh quantities of the car- 

 bonate, must be made. 



The following remarks relate to some curious properties of this 

 substance. If an excess of caustic potash be added to gelatinous 

 pectic acid in a platina crucible, and gradually heated and agitated, 

 the mixture soon liquefies and becomes brown. So soon as, by 

 gradual evaporation, the whole of the water is dissipated, the saline 

 matter, by careful management of the heat, becomes rapidly white. 

 By examination it is then found that the alkali is nearly neutralized ; 

 and that, when dissolved, nitric acid evolves a little carbonic acid, 

 but no pectic acid ; and, by further examination, the potash will be 

 found neutralized almost entirely by oxalic acid, formed at the 

 expense of the pectic acid first added. 



Pectic acid being boiled for an hour with cream of lime, a sub- 

 stance very like oxalate of lime was produced ; but the existence of 

 oxalic acid was not decisively ascertained. No pectic acid, how- 

 ever, remained unaltered. 



This remarkable conversion of pectic acid into oxalic acid, under 

 the influence of weak alkaline action, may be explained in two 

 ways: — 1. The action of the alkali may be something like that o. 

 nitric acid, on the same body, occasioning a derangement of its 

 elements, and producing oxalic acid — a compound, which appears 

 to be one of the last which occurs in the organic scale : or, 2. Pectic 

 acid may be composed of oxalic acid and gelatinous matter, which 



