APPENDIX I. 75 
the alga, also that of the alcohol. Separate the fluid and 
evaporate the alcohol in a porcelain dish, and observe the 
residue, which is chlorophyl. 
(6) Gelatine. 
To some nostoc or spirogyra on a glass slide add ordinary 
coloring matter, as black or red ink. Does the coloring matter 
come in contact with the cell walls? Why ? 
(ec) Alcohol. 
After a quantity of yeast plants have grown. rapidly for 
some time in a flask, and have become “sour” as to odor, 
connect with a still and evaporate slowly. Test a small quan- 
tity of the first portion of the distillate by applying a lighted 
match; the burning is due to the presence of alcohol. 
EXPERIMENT 15. TO SHOW TRANSPIRATION. 
Take a vigorous leafy shoot and insert its cut end through 
a cork into a bottle of water. Cover with a bell jar, and in a 
short time observe the moisture on the inside of the bell jar. 
Explain its source. In an exposed shoot prepared in the same 
manner weigh from time to time, and observe loss of weight 
of the shoot, and explain. 
EXPERIMENT 16. TO SHOW ROOT PRESSURE. 
Cut off the stem of a young, actively growing plant a short 
distance above the soil, and fasten to the stump, by means of 
a rubber tube of about the same size as the stem, a glass tube 
at least three feet long. Into the tube pour enough water to 
cover the cut end of the plant, and support the whole apparatus 
by proper means. Observe the height to which the water rises. 
Does it rise from the first ? 
Another method is to attach a tube bent in the shape of a 
modified 8, with the free arm of considerable length, to the 
cut-off stump of a plant. Fill the tube by first pouring in a 
little water and then mercury, so that the latter stands at the 
