NET DETERIORATION IN LAKE ERIE 175 



appearance 2817 is also stiff and the solvent is not as easy to procure 

 as kerosene, which has been used as a solvent elsewhere with results 

 that were nearly as satisfactory as those obtained on Lake Erie. 



Treatment 282, 284, and 287 produce twines which have more 

 flexibility than some of the others and weigh far less than 2811 and 

 2818. This is a point to be considered in connection with the lifting 

 and washing of nets. They all resemble very closely the cuprous- 

 oxide treatment described above which may be used with the same 

 expectation of success as with these variations. 



Treatment 2825 has flexibility but may cause knots to slip, as will 

 2815; the first is also too expensive to consider seriously. The latter, 

 copper oleate, might well be replaced by copper resinate (2817) in 

 every connection for which it is used for net preservation, since this 

 material is resinous, not slippery like copper oleate. Heavy treat- 

 ments using cuprous oxide will not prove economical unless it is very 

 important indeed to leave the net in the water as long as possible 

 (without washing and drying) at any one time. 



The results of these studies, while performed in fresh water, are 

 applicable to many problems encountered in salt water. In con- 

 cluding the recommendations, it must be said again that the simplest 

 of treatments and unceasing care will give excellent results; the best 

 treatments when poorly applied to nets which are not washed as 

 frequently as possible, will not prevent deterioration of the twine. 



The reader may be interested in the following publications of the 

 Bureau of Fisheries on the subject of net preservation which may be 

 purchased from the Superintendent of Documents, Government 

 Printing Office, Washington, D. C, at the prices stated: 



Taylor, Harden F. 



1920. Preservation of fish nets (with citation of literature). Fisheries Doc- 



ument No. 898. Appendix IV to the Report of the United States 

 Commissioner of Fisheries for 1920, 35 p. Washington. 10 cents. 

 Taylor, Harden F., and Arthur W. Wells. 



1923. Properties and values of certain fish-net preservatives (with bibliog- 

 raphy). Fisheries Document No. 947. Appendix I to the Report 

 of the United States Commissioner of Fisheries for 1923, 71 p. 

 Washington. 15 cents. 



1925. Further experiments on the preservation of fish nets (with bibliog- 



raphy). Fisheries Document No. 998. Appendix VIII to the 

 Report of the United States Commissioner of Fisheries for 1925, 

 31 p. Washington. 10 cents. 



BIBLIOGRAPHY 



Bright, T. B. 



1926. The microscopical examination of damaged cotton hairs by the Congo 



Red test and the swelling test of Fleming and Thaysen. Textile 

 Institute, Journal, transactions, vol. 17, 1926, pp. T39&-T404. 

 Manchester, England. 



DuBos, Rene J. 



1928. The decomposition of cellulose bv aerobic bacteria. Journal of Bac- 

 teriology, Vol. XV, 1928, pp. 223-234. Baltimore, Md. 



Fleming, N., and A. C. Thaysen. 



1921. On the deterioration of cotton on wet storage. Biochemical Journal, 



Vol. XV, 1921, pp. 407-414. Chicago, 111. 

 Gerretsen, F. C. 



1915. Het oxydeerend vermogen van den boden in verband met het uitzuren. 

 Mededeelingen van het Proefstation voor de Java-Suikerindustrie, 

 Deel V, 1915, pp. 317-331, 2 figs. Soerabaia, Java. 



