ACIDS AND ALCOHOLS 141 



Lactic Formed by the bacterial fer- 



C^HfiOs (CH3-CH(0H) - mentation of milk sugar (lac- 

 COOH) tose), also by bacterial fer- 



mentation in sauer kraut and 

 ensilage. 

 Oxalic Free or as acid or neutral salts 



C2H..04(COOH-COOH) of Ca, K or Na in Oxalis, 



Rumex, Rheum, etc. Very 

 abundant as Ca salt in the 

 form of crystals. 

 Succinic In green grapes, and in 



C4H6O4 (COOH — CH2 — CH2 various Papaveraceae and As- 

 -COOH) terales. 



Dextro-tartaric Free and as acid salt of K in 



C4H606(COOH-CH(OH)- fruit of grapes and in other 

 CH(OH)-COOH) fruits. 



Malic Very widely distributed as 



C4H6O5 (COOH-CH2-CH- free acid in fruits, e.g. apple, 

 (OH)— COOH) barberry, grape; in leaves of 



Crassulaceae, etc. 

 Citric Free in fruits of Citrus 



C6H807(CH..(COOH)-C- (orange, lemon, etc.), goose- 

 (0H)(C00H)-CH2(C00H)) berry, etc. 

 Benzoic In fruit of cranberry and in 



CtHoO. (C6H5(C00H)) various gums. 



Salicylic In flowers of Ulmaria and as 



CtHsOs (C6H4(0H)(C00H)) an ester in Wintergreen. 

 Gallic In insect galls, tea, etc. 



C7H6O5 (Cr,H.(0H)3(C00H)) 

 Gallotannic (tannin) In great abundance in many 



C14H10O9 (= two molecules of i)lants; the chief tanning sub- 

 gallic acid united, less H2O) stance. 

 Alcohols. 



Methvl As an ester in some fruits; 



CH4O (CH3(0H)) i)roduced by dry distillation of 



wood. 

 Ethyl Produced in the anaerobic 



C2H6O (CHa -CH.,(OII)) stage of respiration of glucose. 



The chief product (together 

 with CO2) of fermentation of 

 glucose by yeasts. 



