114 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



slow. Negligence in this matter and any overcharging of the tank will result in 

 inefficiency. A second and smaller tank may be used if it is necessary to continue 

 operations when this tank is being cleaned. 



At the fuel-gas works a separation or subsidence tank, in addition to the one now 

 in use, is very desirable. This may be similar to the one described for the oil wells. 

 The depth should bo 12 feet and the diameter 16 feet. It should be designed so that 

 tbe inflow will be evenly and smoothly distributed, with partitions arranged so as 

 to prevent currents, and with the outlet pipe placed 5 feet above the bottom aud 

 extending two-thirds the way across the tank and so perforated as to permit an 

 even flow. The outlet pipe will discharge near the level of the inflow, and all the 

 ordinary water and washings will flow off by gravity. The oil waste at the top and 

 the tarry waste at the bottom may be emptied when necessary. 



Some repairs and modifications of the tank now in use are desirable, and proper 

 attention to its cleaning and operation will be necessary. 



The expense of following out the recommendations made will not be great. 

 Wooden tanks, partitions, and drains are suitable for the purpose. The waste 

 products obtained will he of some commercial value, and at least will not be difficult 

 to dispose of. The location is such that the tanks may receive and discharge the 

 liquid without pumping. 



To summarize my report, I may repeat : 



(1) That oil waste escapes from the oil wells and from the fuel-gas works into the 

 Wabash River in noticeable quantities, although the total amount is not large. 



(2) That this waste may readily be separated from the waste water by inexpen- 

 sive subsidence tanks. 



I ship by American Express to-day a sample taken from the flow from the well of 

 the Phoenix foundry; a sample of sewage from the canal sewer on Ninth street, near 

 Sycamore, which receives the waste from the oil wells ; a sample of sewage from the 

 mouth of the sewer at the foot of Eagle street; a sample of the waste which passes 

 into the sewer from the works of the Citizens' Fuel and Gas Company, and also a 

 sample of the waste from the works of the Terre Haute Gaslight Company. 



DISEASES OF FISHES. 



Dr. R. R. Gurley continued during the year Ms researches respecting 

 the parasites and diseases of fishes. His paper on the Myxosporidia or 

 protozoan parasites, which are the cause of considerable mortality among 

 fishes, was finished early in the year, although assigned a place in the 

 annual report for 1891-92, the publication of which was at that time 

 not completed. Several cases of disease and mortality among the eggs 

 and young fish at some of the hatching stations were made the subject 

 of investigations, the most important being furnished by the station at 

 Northville, Mich., where, during the spring of 1894, a very high death 

 rate occurred among the yearling and two-year-old brook trout stored 

 in the ponds at that place. Dr. Gurley was sent to the station and 

 remained there several weeks, but despite the comprehensive scape 

 of his inquiries the true cause of the difficulty failed to be discovered, 

 or, at least, no effective remedy was found. The diseased fishes were 

 infested to a greater or less extent with well-known parasites of two 

 or more varieties, but it could not positively be said that they were the 

 chief instrument of death, even if they were concerned in it at ail. 



