BULLETIN 
OF THE 

ILLINOIS STATE LABORATORY 

VoL. XI. 

OF 

NATURAL, HISTORY 

UR BANA, ILLI NO IS, U. S. A. 

STEPHEN A. FORBES, Pu .D., LL.D., 
DIRECTOR 

l\L\Y, 1918 ARTICLES VIII-X. 

ART. VIII. T HE REACTIONS AND RESISTANCE OF FISHES TO 
CARBON DIOXIDE AND CARBON l\IONOXIDE 

BY 

;\loRRIS :u. WELLS, P11.D. 

ART. IX. · EQUIPMENT FOR l\IAINTAINING A FLOW OF OXYGEN­
FREE WATER, AND FOR CONTROLLING GAS CONTENT 

BY 

VICTOR E. SHELFORD, PH.D. 

ART. X. A COLLECTING BOTTLE ESPECIALLY ADAPTED FOR THE QUAN­
TITATIVE AND QUALITATIVE DETERMINATION OF DISSOLVED 
GASES, PARTICULARLY VERY S:\IALL QUANTITIES OF OXYGEN 

BY 

EDWIN B. POWERS, M. A. 



ERRATA AND ADDENDA. 

Page 50, second column, line 13 from bottom, for Danais archippus read Anosia 
vlexi]Jpus; line 8 from bottom, for mellifica read rnellifera. 

Page 51, line 11 from bottom, for Danais read Anosia. 
Page 159, at right of dia~ram, for Brac;on agrilli read Bracon agrili. 
Page 289, second column, last line but one, for Scalops real Scalopus. 
Page 294, line 3, for catcsbeana read catesbiana. 
Pages 327 and 330, line 12, for orcus read oreas. 
Page 347, line 4, for Cecidomyidre read Cecidomyiidre. 
Page 356, line 7, for Anthomyidre read Anthomyiidre. 
Page 368, line 18, dele second word. 
Page 373, after line 10 insert as follows: 53a, subvruinosa Casey, 1884, p. 38. 
Page 375, after subinucida Le Conte, 48, insert subpruinosa Casey, 53a. 
Page 377, after line 7, insert as follows:-

1884. Casey, Thomas L. 
Contributions to the Descriptive and Systematic Coleopterology or 

North America. Part I. 
Page 379, line 11 from bottom, for sens·u lata read sensu lato. 
Page 382, line 12, for VII read VIII. 
Page 408, line 2, for the next article in read Article VIII o,t. 
Page 410, line 6 from bottom, for = 4 read '11. 
Page 412, line 7, for 31 read 30. 
Page 421, line 17 from bottom, insert it before grows. 



ARTICLF. X.-A Collecting Dottle especially adapted for the Q11an­
titatfr,1c and Qualitative Dctcrmi1wtio11 of Dissolv ed Gases, partirnlarly 
,•cry Small Qualllitics of Oxygen.* 13v EDWIN B. Pow1ms. 

One of the sources of error in the Winkler method for the de­
termination of dissolved oxygen in water, especially where the oxygen 
content is low, is the diffusion of oxygen into the water before and 
during the introduction of the chemicals. Another source of error is 
the mixing of the manganous chloride with the potassium iodide­
alkali solt1tion at the surface of the water, the chemicals adhering to 
the pipettes introducing these reagents having washed off at the top 
of the bottle, where they react with the oxygen present. In recent 
work involving the oxygen-free water apparatus described by Shelford 
in the preceding article of this vol11me, it was found especially de­
sirable to eliminate the above sources of error. This was accomplished 

d e 
C 

a 

*This bottle was devise,] primarily for the study of t.be oxygen requirements of 
crayfishes, with a view to their n~e ns index orgnnisms. 

577 



578 

by a special bottle which allows the collecting of samples and the in­
troduction of the chemicals without exposing the samples to air during 
the operation. 

The apparatus shown in the accompanying figure is composed of a 
bottle having an inlet, a, at bottom and an outlet, b, at top. vVhen the 
bottle is filled the inlet is clamped off at c. The manganous solution is 
introduced through the burette d and the potassium iodide-alkali sol11-
tion through the burette c. The burettes d and c are supplied with a 
two-way stop-cock at f. The displaced water is allowed to pass out at 
the outlet b, which is kept open to equalize the pressure. The acid 
solution is introduced through the burette d, thus avoiding any action 
of a strong acid on the potassium iodide of the potassium iot!itlc­
alkali solution. A 200 c.c. pipette is used to draw a sample for 
titration, thus avoiding agitation of sample in presence of air. Cor­
rection for error due to the introduction of chemicals can be calcu­
lated from the per cent. of collection used for titration with sodium 
thiosulphate, and the oxygen content of the water can be calculated 
directly. In lieu of the simple pipette for drawing off sample of water 
for titration, the device described by Hyman L. Shoub* may be sub-
8tituted. 

A modification of this bottle is also very useful for work with 
hydroge0 sulphide, sulphur dioxide, carbon dioxide, and other gases 
when exclusion from the air is essential. 

I wish to thank Mr. Carl F. Miller and Mr. Paul Anders, of the 
Chemical Laboratory of the University of Illinois, for making this 
apparatus available. 

*Hygienic Lah. Bull. 96, U. S. P. H. S. Aug., 1914.