384 BOTANICAL GAZETTE [MAY 
Bog water has now been studied from a number of widely distant 
localities, namely: from Aetna and Millers, Ind. (at the southern end 
of Lake Michigan); from Oconomowoc, Wis.; from Grand Rapids, 
Mich.; from Ann Arbor, Mich.; from Toms River, N. J.; and from 
near Port Jervis, N. J. The results obtained are tabulated below, 
=" with a brief characterization of the flora of the bogs. Data 
for ;4» sea water are given for comparison. In the table, lowering of 
the freezing point, due to dissolved substances, is given in degrees 
centigrade. The osmotic pressure is given in millimeters of a mer- 
cury column and also in terms of M, which represents the, pressure 
developed in a molecular solution of any non-electrolyte. 
TABLE OF PHYSICAL PROPERTIES OF NATURAL WATERS. 
PGuenic or CALCULATED 
Source or WATER NAtTuRE OF VEGETATION etal Poor Osmoric Pressure 
(degrees C.). |[—_+~—__— 
Mm.of Hg M 
rained s mg ae of Hacken- 
wate Rivers 0.005 50.075 10000 
ew York ci supply (Croton 
c — Bronx Riv 0,005 50.075 yoves 
icago city supply (Lake 
Michigan), 0.0% 100.15 1000s 
= River, Grand. Rapids, BR 
Poses Wire wets 0.0r 100.15 10000 
Metin Ines ie oe Rhus Vernix, —- 0.01 00.15 10900 
cate Ind.. Larix, Rhus Vern 0,005 eo O75 radoo 
mowoc, Wis.3. ....|Typical Larix bee 0.02 gaia dat dt be 
Grane Rapids, Michio. Saas Sphagnum, aoe. 0.015 150.225 10000 
n Arbor, Mich,: 9 
as irst Lake Bog4........... Larix, LS emeenieenst, Sphag- 0.005 50.075 10000 
num. 
West Lake Bog 5...-...... Er tein Chamaedaphne, Po- 0.0125 125.188 10808 
tentilla palustris, Salix. 3 
Average of 13) 57.086 To000 
Toms River) Noi esc. Chamaecyparis, = at tests, 0,0057 pe 
meetapines Sar Max., 0.017 170.26 10090 
in,, 0.0025 25.038 TOvGT 
Pore Jervis: Ni; 9.60 oor is Bf Phe one Chamaedaphne. 0.006 60,090 10000 
yb0 Sea water... .. 0.0225 250.075 13380 
3 This water was obtained for me by Dr. H. C. Cowles. 
4 This lake and its bog are described es Spe by Wexp, L. H., Botanical survey of the Huron 
River Valley. II. A p Bor, Gaz, 37: 36-52. 1904. 
5 This lake and a are guise by ae . S., A botanical survey of the Huron River ee 
I. The ecology of a glacial lake. Bor, Gaz. 34: 125-139. 1902, These Ann Arbor waters were obtaine 
by the kindness of Mr, E, N, Transeau, 
6 This water was obtained through the kindness of Dr. C. C. Curtis, of Columbia University. 
The tests here recorded were made in the summer, autumn, and 
winter, several bogs being studied both in the dryest part of the former 
season and in the middle part of the latter. These last-named tests 
showed practically no difference in osmotic pressure corresponding to 
