202 GIBBS. 



certain bacteria that transfonn sugar mainly into lactic and acetic acids. The 

 higher the temperature of fermentation the greater the development of mannite. 

 In all cases the formation of mannite indicates a deterioration of the winel 



Browne'" states: "The most common fermentation which the raw juice of the 

 cane undergoes in Louisiana, is not alcoholic, as might be supposed, but a fer- 

 mentation designated variously as viscous, mucilaginous or mannitic. This fer- 

 mentation is anaerobic in character * * *" and "It was at first supposed that 

 the mannite was the product of a special organism, but this is a mistake, for 

 mannite may be formed in any fermentation of sugar where a reducing action 

 takes place. The quantity "of mannite in femiented juices will vary; juices which 

 showed over 2 per cent mannite were found on subsequent analysis to be nearly 

 deficient in the same, owing to the fact that other fermentations had set in 

 whereby the mannite was destroyed." 



Balland "* found 5.6 per cent mannitol in the palrii Avine from Laghouat, 

 Arabia, made from the sap of a 40-year-old date palm. 



Dunstan'"' found approximately 1.8 per cent of mannitol in the water obtained 

 from Ceylon> coconuts, while that from a sample of ripe nuts, "as imported into 

 the United Kingdom," contained none. The former, he states, appears to be 

 abnormal in containing mannitol in place of almost all of the glucose usually 

 present. 



"It would be interesting to know whether this replacement of glucose and 

 cane sugar by mannitol constantly occurs in nuts grown in Ceylon, or whether 

 it is characteristic of a particular variety of nut. It is worth notice that man- 

 nitol is very closely related to glucose, and that it is possible that the presence 

 of mannitol in this sample of 'water,' may be due to a change similar in 

 character to the mannitol fermentation, which occasionally takes place in wine, 

 whereby the sugars normally present in the wine are partially converted into 

 mannitol." 



From these considerations it is evident that mannitol will be found to 

 occur in the palm saps which have fermented at the high atmospheric 

 temperatures of this region, 30° and over, where no care has been taken 

 to control the fermentation, even though it may not have been present 

 in the sap as it issued from the tree.^" 



I have examined a number of samples, over twenty, of the saps of 

 the buri {Corypha elata Eoxb.), coconut {Cocos nucifera Linn.), cabo- 

 negro {Arenga saccharifera Labill.) and the nipa. {Nipa fructicans 

 Wurmb.) and have found the majority of the samples to be practically 

 free from mannitol, or, at the most, only traces have been present. 

 The largest amounts were encountered where the fermentation of the 

 sap had proceeded to a considerable extent. One sample of the Arenga 

 to which formaldehyde had been added as a preservative contained 4.0 

 per cent of mannitol, which was the largest proportion found. This 



"VoMra. Amer. Chem. Soc. (1906), 28, 459; 462. 



^o^Gompt. rend. Acad. Sci. (1879), 89, 262. 



^"'Trop. Agr. & Mag. Ceylon Agr. Soc. (1906), 26, 377. 



"» In this connection it is interesting to recall the equilibrium which has been 

 found by Lobry de Bruyn to exist under certain conditions between glucose ^ 

 fructose ^ mannose. 



