FISH-IsrET PRESERVATIVES. 



19 



The other preservatives exposed at Beaufort showed no preserv- 

 ing effect worth considering. These were quercitron and potassium 

 bichromate, I; petroleum products, Nos. 1 and 2, J and X; and 

 gilsonite, S. These materials and methods may be definitely elimi- 

 nated by this experiment, since they do not preserve. 



45 

 44 

 42 

 40 

 38 

 36 

 34 

 32 



30 



»o 

 §28 



=> 

 o 

 |26 



X 



•- 24 



z 



?f22 

 <o 



uJ 



^20 



lie 



16 

 14 

 12 

 10 



8 

 6 

 4 



Z 







12 3 4 5 6 7 



MONTHS EXPOSED 



Fig. 6. — Tensile strength of cotton lines exposed in sea water at Beaufort, N. C, 

 grouped. 



The results of these experiments show also that lines suffer deteri- 

 oration mucli more rapidly at Beaufort than at Key West. This 

 applies equally to untreated lines and to those treated with pre- 

 sei*vatives. 



FLEXIBILITY. 



If preservation of tensile strength on exposure were a sure and 

 sufficient criterion, it would now be proper to pronounce copper 



