234 RESEAKCHES UPON" THE CHEMICAL PROPERTIES OF &ASBS. 



PopofF finds in a gas from decaying vegetable matters : 



Marsh gas 68 56 per cent. 



Carbon dioxide 31.44 " 



Berthelot states that hydrogen is produced in the vinous fermentation of mau- 

 nite. In very careful experiments which I have tried I have failed to find hydrogen 

 in the gas evolved daring the fermentation of 200 gms. of sugar. Chemical changes 

 of this type are not likely to be of importance, however, as regards the hydrogen 

 question. 



GASES PROM SEA WEEDS. " 



The following experiments were tried in order to study the nature of the gases 

 evolved in the decay of sea weeds : 



A quantity of a large fiicus kind from Santa Barbara, Cal., was used, 50 gms. 

 of the air-diied plant were soaked in water and then introduced into a flask filled 

 with water, which had been previously boiled (in order to expel air) and cooled. The 

 flask was connected with a belljar over a mercury trough. After setting up the 

 apparatus, no gas appeared until the third day; then a strong evolution of gas 

 began and continued in slowly diminishing quantity for ten days, when the process 

 ceased. In all, 803 c.c. of gas were collected. Analyses were made (1) of the first 

 portion of 300 c.c, (2) of a second portion of 300 c c, and (3) of the last portion 

 of 203 c.c. The results are tabulated below. 



FIRST PORTION. 



Carbon dioxide 18.23 per cent. 



Carbon monoxide 



Ethylene 



Methane 0.30 



Hydrogen 63.a4 



Nitrogen 19.23 



SECOND PORTION. 



THIRD PORTION 



32.47 pel 



- cent. 



53.44 per cent. 























0.28 





0.08 " 



48.97 





43.02 " 



18.28 



( 



4.46 " 



100.00 100.00 100.00 



Carbon dioxide was determined by soda solution over mercury ; hydrogen by 

 palladium asbestos, using a Hempel apparatus. The absence of CO and C2H4 was 

 proved by palladium chloride solution. Methane was determined by combustion 

 with air, using a red-hot platinum tube. The carbon dioxide produced in the com- 

 bustion was absorbed by baryta solution of known strength, and the excess of 

 baryta determined by standard oxalic acid. The following facts are of especial 

 interest : 



1. The carbon dioxide increases towards the end of the decay. 2. The hydro- 

 gen steadily diminishes. 3. Methane occurs only in traces. 4. I^itrogen occurs in 



