ACIDS AND ALCOHOLS 141 
Lactic 
C;H,O; (CH; -CH(OH) — 
COOH) 
Oxalic 
C.H.O, (COOH —COOH) 
Succinic 
Formed by the bacterial fer- 
mentation of milk sugar (lac- 
tose), also by bacterial fer- 
mentation in sauer kraut and 
ensilage. 
Free or as acid or neutral salts 
of Ca, K or Na in Oxalis, 
Rumex, Rheum, etc. Very 
abundant as Ca salt in the 
form of crystals. 
In green grapes, and in 
C,H;,O, (COOH —CH:—CHg: various Papaveraceae and As- 
—COOH) 
Dextro-tartaric 
terales. 
Free and as acid salt of K in 
C,HsO. (COOH —CH(OH) — fruit of grapes and in other 
CH(OH) —COOH) 
Malic 
C,H,O; (COOH —CH: —CH- 
(OH) —COOH) 
Citric 
CsHs07 (CH.(COOH) —C- 
fruits. 
Very widely distributed as 
free acid in fruits, e.g. apple, 
barberry, grape; in leaves of 
Crassulaceae, ete. 
Free in fruits of Citrus 
(orange, lemon, etc.), goose- 
(OH)(COOH) —CH.(COOH)) berry, ete. 
Benzoic 
C7H,.O2 (CsH;(COOH)) 
Salicylic 
In fruit of cranberry and in 
various gums. 
In flowers of Ulmaria and as 
C:HsOs (CsH«4(OH)(COOH)) an ester in Wintergreen. 
Gallic 
C;HeO0; (CsH2(OH)3(COOH)) 
Gallotannic (tannin) 
In insect galls, tea, etc. 
In great abundance in many 
C4Hi00s (= two molecules of plants; the chief tanning sub- 
gallic acid united, less H,O) stance. © 
Alcohols. 
Methyl 
CH,0 (CH;(OH)) 
Ethyl 
C:H.O (CH; —CH,(OH)) 
As an ester in some fruits; 
produced by dry distillation of 
wood. 
Produced in the anaerobic 
stage of respiration of glucose. 
The chief product (together 
with CO.) of fermentation of 
glucose by yeasts. 
