1908] DACH NOWSKI—TOXIC PROPERTY OF BOGS 137 
value of the solutions (19). Other criteria employed were the con- 
dition of the roots, green and dry weight of plants, length and 
anatomical structure of roots, stem, and leaves. None of these alone 
can be regarded as accurate measures of plant activity, but taken 
together they generally agree in indicating the relative value of the 
results. Without dwelling here at length upon the exact data derived 
from these experiments, only the results in transpiration-increase are 
given below intabularform. The percentage increase in transpiration 
is calculated for the larger number of the plants upon the basis of 
the quantities for the bog soil solution considering it as unity. 
TABLE II 
PERCENTAGE INCREASE IN TRANSPIRATION 
o a as 
i o rh 32 
Culture soluti 3 g i 2 | 38 E 3 § 3 : 
on Ss é Z2 8 ra a 3 6 a é 
I. Central zone: 
1. Bog soil extract*.... . . ° fe) ° ms ; 
2, water untreated. 19 | 16] 113 | 22} 68 A es 
3. Bog water aerated... 5 27 | 201 ee ais 8. 
4. Bog water neutral. ... 209 gI Too ee oe 
5 Bog water filtered 245 52 | 225 | 215 94 /38.8 47 oF 
og Wher fo: 8 ace 
II. Maple-alder zon 7 pa oe 
1. Bog soil extract*,... ° fo) ; 
2. Bog water untreated. 38 | 65 | 287 = 
3- Bog water aerated... 164 
Bog water neutral... 298 | 136 | 335 i 
$ Bog water filtered... __ 256 76 
- Bog plant water....... I 40 | 178 ed 
gm % 
*4°™ of bog soil and 400° distilled water. 
An increase in the dry weight of roots and tops was obtained in 
all plants growing in the solutions treated with CaCO, and carbon 
black. For the corn and wheat respectively the increase in the 
7 Matter produced varied from 20 per cent. to 50 per cent. during 
the time of the experiment. 
It will be observed that the evidence derived from wheat, corn, 
bean, elm, and buckeye seedlings (two years old), and other plants 
yields results and conclusions similar to those pointed out for mar- 
‘hantia. The plants grown in the bog soil extract and in the untreated 
veal show stunting clearly in the roots. The tops of the plants 
ore nearly alike, except in the stronger solutions. Marke 
