PRESENCE OF A TRUE MANNA ON A BLUE GRASS. 301 
From the above results we have the following analysis :— 
Substances soluble in water = 72°42 per cent, 
Substances insoluble in water = 27°58 is 
Moisture bis tvs oe =e ... = 17:190 per cent, 
Mannite ss ves wee eee ... = 58-000 ” 
Glucose wie cas ee aoe vos oe 21D +s 
Other sugars ... i Te oe Ce ae tf eee 
Gum soluble in water bt. ede say, et 2400 " 
Soluble in alkali ? gum ves ‘vi ... = 1780 x 
Soluble in acid ? gum... ees ia pus “BSD Ps 
Ash : ao. ™= . 2000 ” 
Debris, ‘dirt, pie oe. Scumnindicen fungus = 22-720 4 
Nitrogenous bodies etc. undetermined, and loss= 1-405 a 
100-000 
We may therefore consider that the chief product of this grass 
manna is mannite. 
Fermentation of the Manna with Yeast.—0°9 gram of the manna 
was dissolved in water, mixed with a little fresh yeast, and placed 
in a graduated tube over mercury.? 
The readings were taken the first thing in the morning in every 
case, the temperature then being about the same. 
The first twenty-four hours gave 1-7 cc. of gas. 
» second + ” 2-0 ” 
» third “3 ” 2-2 ” 
» fourth * eae 9 
9 GECh ~ Me is ” 
» sixth 9 ” 37 ” 
» seventh a Sd | ” 
» eighth 3 Pe ” 
Wate ee pairing i 
1 For comparison a portion of cane-sugar was inverted, neutralised, 
made slightly acid with tartaric acid, yeast added in the same proportion, 
and placed by the side of the manna determination. Fermentation 
rapidly set in, and the whole was destroyed in twenty-four hours, no 
further action taking place after that time. 
