COMPARATIVE EXAMINATION OF MUCOUS ACID. >7 



I observed, that, in proportion as the mucous acid was Alteration in 

 deprlvet! of the oxalate of lime, that rendered it impure, it anceof the 

 uoq ui ltd a more floiculent appearance. acid. 



To ascertain, whether the mucous acid obtained from the Mucous acid 



sut>ar of milk, in which it was first discovered by Scheele, Prepared from 

 ^ ' ... sugar of milk, 



were likewise contaminated with oxalate of lime, I boiled by way of 

 a similar cjnautity of sugar of milk with eight parts of ni- comparison, 

 trie acid of the same strength as before. The lirst por- 

 tions of mucous acid formed I separated by decantation, 

 and added to the residuum a fresh quantity of nitric acid. 

 A Kccond portion of mucous acid was deposited, which, 

 added to the first, made up the weight of 12 gram. [185*3 

 t;rs.],,or a fifth of that of the sugar of milk employed. 



1 remarked, that this mucous acid, after washing, when This appa- 

 d iff used in water had as flocculent an appearance as that ""^"^'y I'"'** 

 from the gum, when it had been deprived of its oxalate of 

 lime by dilute arid. This led me to presume, that the 

 acid was mt\ch purer than that from gum ; and my con- 

 jecture was soon confirmed by nitric acid having no action 

 on it. This acid covild not take up from it the smallest 

 quantity of oxalate of lime in a long continued digestion, 

 for ammonia did not produce the slightest cloud in the su- 

 pernatant liquid. - - ■ 



What bcfeides'left no doubt of the perfect purity of the The acid from 



mucous acid from sut^ar of milk was its easy and complete f '"" "°^ P"' 



. . . - . lectly pure 



solution in boiling water. This even proves it to be more when fre6"d 



pure than the mucous acid from i^um, after it has been de- ^'?"^ oxalate 



. , o ' ^ of lane, 



prived of oxalate of lime by the means mentioned above : 



for the latter, when boiled with distilled water, leaves an 

 ifiyoluble flocculetit matter, amounting to 0'0() of its weight ; as it containad 

 which dries in?o a gray, horny, seniitranspurent substance, another sub- 

 much resembling in appearance the mucous matter, that 

 coivnects together the particles of animal concretions; 

 though, when thrown on burning coals, it does not emit the 

 ainmoniacal and fetid smell of animal compounds, and yields 

 by calcination carbonate of lime. The very small quantity 

 I obtained did not allow me to make such expeiiments, as 

 would furni^h u more accurate knowledge of the nature of 

 this substance. 



From the facts tl^at have been mentioned, ^e may ihfi»r; G neral con- 

 ;Voi,.XXVm.— Jan. 1811. -C . Ist, *^^ "'''"*• 



