62 The Botanical Gazette. [February, 
ficient to kill the greater portion of it. It could withstand: 
much longer period of exposure to ether and chloroform 
vapors. | 
The following set of experiments, 4 to 6, relate to the it 
fluence of anesthetics on plant transpiration when the plant 
is exposed to the various colors of the solar spectrum. 
found it rather difficult to obtain pure colors. The colors! 
desired were red, yellow and green. Red and green I wi 
able to obtain quite pure; but it was impossible for me to ob 
tain yellow that did not also transmit red. The following 
is a list of substances with result of spectrum analyses. T 
thickness of the liquid was in all cases 13. 
— 
| 
Color. Dye used. Rays transmitted. 
1 | Eosine .| From 65 to 75. 
2 Carmine From 66 to 73. 
sa sipcall HL) led SayUseneeoesbae ere ee From 68 to 75. 
4 | Safranine From 67 to 75. 
5 Magdala red From 64 to 75. 
1 | Methyl orange From 56 to 75. : 
2} Gold orange From 58 to 75. 
ERPOW ET: OPO R MO a ass tes seelane Sis lkaes tas -| From 57 to 75. 
4 | “Diamond dye” yellow ......cssssscseeees From 55 to 75. 
. a | 
1 | Iodine green ..... From 45 to 56. | 
.2| Methyl green . From 45 to 57, and 72 to 75. 
es 3 | Malachite green From 46 to 56, and 72 to 75. 
reen.| 4 | Alcoholic chlorophyll solution......... From 40 to 70, 
5 Copper chloride solution From 40 to 70. 
6 | Diamond dye yellow and blue.........| From 49 to 56. 
Black.| x | Diamond dye black Faint trace of all rays. 
White, |x 4- Water: es All rays of solar spectrum. 
From these and various other colors which I examined, 
selected fuchsine for red; ‘‘diamond dye” yellow, for yell 
a mixture of diamond dye yellow and blue, for green. ~ 
of the ordinary bell-jar. Diamond dyes have an adva® 
in that the watery solutions do not form a sediment like mat 
of the aniline dyes; they seem also to fade less quickly. 
The transparency of colored liquids was made approxima®: 
alike, likewise was the thickness of the liquids in the vat 
Jars, and different parts of the same jar only approxi 
Owing to the fact that a complete series of experiments 
