Bulletin Illinois State Laboratory Natural History Urban A, Illinois, U. S. A. STEPHEN A. FORBES, Ph.D., LL.D., Director Vol. XI. May, 1918 Articles VIII-X. ART. VIII. THE REACTIONS AND RESISTANCE OF FISHES TO CARBON DIOXIDE AND CARBON MONOXIDE BY Morris M. Wells, Ph.D. ART. IX. EQUIPMENT FOR MAINTAINING A FLOW OF OXYGEN- FREE WATER, AND FOR CONTROLLING GAS CONTENT BY Victor E. Shklford, Ph.D. ART. X. A COLLECTING BOTTLE ESPECIALLY ADAPTED FOR THE QUAN- TITATIVE AND QUALITATIVE DPiTERMINATION OF DISSOLVED GASES, PARTICULARLY VERY SMALL QUANTITIES OF OXYGEN BY Edwin B. Powers, M. A. ERRATA AND ADDENDA. Page 50, second column, line 13 from bottom, for Danais arcMppus read Anosia plexippns ; line S from bottom, for melliflca read mellifera. Page 51, line 11 from bottom, for Danais read Anosia. Page 159, at right of diagram, for Bracon agrilli read Bracon agrili. Page 289, second column, last line but one, for Scalops real Scalopus. Page 294, line 3, for c.atesheana read catesiiana. Pages 327 and 330, line 12, for oreus read oreas. Page 347, line 4, for Cecidomyidae road Cecidomyiidae. Page 356, line 7, for Anthomyidse read Anthomyiidae. Page 368, line 18, dele second word. Page 373, after line 10 insert as follows: 53a, suipruinosa Casey, 1884, p. 38. Page 375, after suXimucula 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 of North America. Part I. Page 379, line 11 from bottom, for sen.iu lata read sensu lato. Page 382, line 12, for VII read VIII. Page 408, line 2, for the next article in read Article VIII of. 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. Article IX.- — Equipment for umintaimng a Flow of Oxygcn-frcc Water, and for controlling Gas Content* By Victor E. ShivLFord. In Article VI of this volume a piece of apparatus for controlling gas content and adding gases and fluids to water is described l)y the present writer. His earlier work, as well as that reported by Dr. Wells in Article VIII, was done with that apparatus on a water table of temporary construction, Init the table and the apparatus have both been replaced by the permanent structures herein described. The new equipment consists of a large drain-table (13), shown in the lower part of the accompanying figure, with the boilers on the floor above. The drain table is provided with double-decked towers nine feet high, for supporting bottles, tanks, etc. in the manner indicated in articles VI and VIII of this volume. Aside from possessing many advantages in the control of conditions where fluids and gases are added, the new apparatus has great advantages in the control of oxygen content, as continuous flow is insured, and with aerating troughs of various lengths almost any amount of oxygen can be obtained in running water. The other apparatus! used gas heat for boiling and could de- liver not more than 100 c.c. of oxygen-free water per minute, and this amount was not certain to be free from oxygen continuously. The new piece of apparatus delivers a liter of water per minute and could probably deliver a maximum of four or five liters per minute. It uses high pressure steam for boiling the water and deliv- ers it with the temperature brought down to that of the water sup- ply. We may accordingly follow the course of the water supply from the supply pipe to the exit from the cooling coil. Water is introduced into the first boiler, No. i, from the supply pipe at the right of the upper group of apparatus. It is passed through a Schuttc & Kocrting lyz" strainer to an inclosed float cock, No. 9. This float cock, a stock article on the market, maintains water at a definite level in both tank *The apparatus describeil in this article nas developed in connection with the work on stream pollution done by the author and described in Article 6 of this volume; the new apparatus was provided by the University of Illinois in the new Vivarium Building to supersede the piece described in that article. The drawing was provided by the Dejiartment of Zoology. tSee Shelford and Alloc, Journal of PlxjicrinKMital Zoology, Vol. 14, pp. 207-266. 1913. S73 574 No. I and tank No. 2. Tank No. i is a water-heater containing a steam coil and vented by two large pipes connected with the flue. A large amount of steam and gas is given off from the water escape from this tank. Tank No. i is connected with tank No. 2 by a two- inch pipe containing a valve which makes possible the draining of one tank without draining the other. The water being withdrawn from tank No. 2, flows from No. i to No. 2 and is boiled for a long time in the latter, which measures 2X2X4 ft. and is supplied with a six-inch vent in a large cover. The water leaves tank No. 2 at the left through a dirt trap, No. 7, and passes through the floor to the room below. The discharge line can be flushed with university water from CW. The steam used is high pressure—usually 90 pounds— but may be reduced to 25 or 30 pounds by a pressure-reducing valve, No. 8; the steam traps. No. 6, remove the condensation. After passing through the floor the water goes through a cooler. No. II, made from block-tin pipe (black iron return bends at the ends) placed inside i ^X" pipes connected with each other by cooler tees, the cooling water flowing into the cooler at the point where the boiled water leaves it. In the middle of the coil are three gas introducers (12), which are modified beer air-purifiers made by Bishop, Babcock, and Becker, the gas being introduced into the chambers, through which the water flows, through blocks of basswood, thus dividing it into very small bubbles. Oxygen, carbon dioxide, and nitrogen have been in- troduced. The water is delivered at the ends of a drain table. Tank No. 3 is used for securing water which is saturated with oxygen under atmospheric conditions in quantity sufficient to run through a number of bottles containing animals. Tank No. 4 is for aerating the univer- sity water-supply by running it down crimped inclines and through two chambers where the iron which is precipitated is removed. This water is stored in tank No. 5. Two tanks like Nos. 4 and 5 are pro- vided above tank No. 3, with the controlling float-cock in No. 3, so that water may be partially aerated and delivered to No. 3, where com- pressed air forced into it renders it very alkaline and saturated with oxygen. The drain table is supplied with water from tanks Nos. 3 and 5 and from the university supplv marked CW, and also with air (A).