30 



SIXTH REPORT — 1S36. 



Crenic and 

 Apocrenic 

 Acids. 



Organic 

 mutter in 

 Springs. 

 Glairine, or 

 so called 

 animal 

 matter. 



acid in a sprins^ at Craveggia in Piedmont, by Vauqnelin; and 

 also in those of Ronneberg*, and Bruchenau in Bavaria. 



More recently Berzelius has described two new vegetable 

 acids in the springs of Porlaf in Sweden, to which he has given 

 the names of the crenic and the apocrenic, both derived from 

 an organic matter present in the water, the crenic first, the 

 apocrenic from the other by the action of oxygen. 



Crenic acid does not crystallize, but its solution in water 

 concentrated to the consistence of a syrup is almost colourless. 

 When dried in vacuo it splits in all directions, and its taste is 

 then distinctly acid and astringent. Though a weak acid, it 

 decomposes the acetates, and combines with the alkalis and 

 alkaline earths. Most of them are insoluble in water, but the 

 protocrenate of iron is soluble. 



The apocrenic acid imparts a brownish colour to water, in 

 which it is but slightly soluble. Its salts resemble the crenates, 

 but are either brown or black, and are insoluble in alcohol. 



Thej' combine with hydrate of alumina when digested with 

 it, and form a colourless solution. 



These two acids were found in several chalybeate waters in 

 Sweden, and may be separated from the ochre which they de- 

 posit by boiling it with potass. 



The crenic acid J, or one much resembling it, has since been 

 detected by Professor Fischer of Breslau in the mineral spring 

 of Landeck in Silesia §. 



The above acids may possibly have some connexion with an 

 organic substance found in most thermal and many cold springs, 

 which has excited much speculation, and been supposed to 

 possess important medicinal qualities. We owe the first accurate 

 information respecting it to Bayen ||, who, in 1765, published an 

 account of the mineral water of Luchon, in the Pyrenees, in 

 which he discriminated this flocculent matter from the sulphur 

 also present. 



In 1786 Dr. Willar.^ described a white mucous substance ex- 

 isting in the waters of Croft, in the county of Durham, which 



* Dobereiner in Kastner's Arcliiv, vol. xvi. 



t Phil. Magazine, vol. vi. p. 239. 



X The crenic acid has lately, it is said, been found to be an ingredient of 

 the Bergniehl of Lapland, which the natives in times of scarcity mix with 

 their flour, considering it to contain nutriment. This material is stated to be 

 chiefly made up of the outer shells of fossil infusoria, together with some 

 animal matter probably derived from their internal substance, and of the acid 

 alluded to.— Phil. Mag. for April 183?. 



§ Jahrbucher Deutsnhlands Hcitquellen. \\ Opuscules Chemiques. 



If On Croft and Harrogate Waters. London, 1786. 



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