278 MILDRED SPARGO 



Carefully observing all of his precautions, an attempt was 

 made to duplicate his experiments. He used a flask covered 

 with wicker packed in a wooden box filled with sawdust, and 

 performed his experiments in a north room where the tempera- 

 ture was low and fairly constant. 



The experiments herein reported were carried on in a base- 

 ment room, where the temperature was rarely higher than 22° C, 

 and varied not more than 5° or 6°. In the earliest experiments, 

 Dewar flasks were used. These were placed in wooden boxes 

 and tightly packed with excelsior. The only part of the flask 

 uncovered was the upper rim of the neck, which was covered 

 with paraffin to obviate any leakage should the cork not fit 

 perfectly. The bulb of the thermometer, in every case, was 

 in the mass of leaves. 



Freshly picked, dry leaves were used (dampness would pre- 

 vent free interchange of air, and would hasten decomposition), 

 and their weight determined. Molisch used from 3.5 to 5 kg. 

 of leaves, never less. Though he gave no dimensions of his 

 apparatus, from the figure accompanying the article it appears 

 to have been a regulation laboratory carboy in its box. 



The half-litre Dewar flasks used held in no case more than 

 75 grams. As no results were obtained in the experiments, 

 flasks of larger capacity were employed in succeeding experi- 

 ments. The following flasks were used; — the half-litre Dewar 

 flasks; 2-litre flasks, which held from 170 to 225 grams; 4-litre 

 flasks, holding 300 to 325 grams (the latter were wrapped in thick 

 folds of soft paper and closely packed in excelsior in a wooden 

 box); and a large carboy of about 12 gallons capacity. This 

 was of thick glass, and was firmly packed in excelsior in a strong 

 wooden box. Not more than 3 kg. of the smallest leaves could 

 be packed into this large carboj^, and the question arises as to 

 what means Molisch used to get 5 kg. into a flask apparently 

 no larger. 



As the tables given below indicate, the leaf-masses used did 

 not affect the results in any way. Attempts were then made to 

 see if the quantity of leaves in a given flask affected the result. 

 One Dewar flask was tightly packed with young Sedum leaves, 



