Taylor and Wells. — Preservation of Nets and Lines. 



37 



TABLE I.— BREAKING STRENGTH OF LINES. 



Number 



Method of treatment 



Strength | Strength 



after 4 I after 10 



weeks weeks 



Bull's method (quercitron, etc.) 



N/10 Copper sulphate and N/10 potassium 

 ferrocyanide 



N/10 Potassium ferrocyanide and N/10 cop- 

 per sulphate 



N/2 Copper sulphate and potassium ferro- 

 cyanide 



Ivory soap and copper sulphate 



Untreated, control 



Kg. 

 7.78 



3.66 



3.22 



4.98 

 7.32 

 1.18 



Bull's method here proved to be best, as a preservative of 

 breaking strength under the conditions described. Next in order 

 is the soap-copper combination. The failure of the copper fer- 

 rocyanide lines was obviously due to faulty impregnation, since 

 the inner strands of the cord were not reached by the preserva- 

 tives. 



Copper soap appeared to deserve further study. Microscopic 

 examination of the fibers showed that the copper soap was not 

 uniformly deposited, but was in the form of an amorphous pre- 

 cipitate. Experiments were next undertaken to effect a better 

 penetration of the fibres and a more uniform distribution of the 

 copper soap- by means of a suitable solvent. Ivory soap, and the 

 copper soap made from it, is a mixture of various fatty acid salts; 

 copper stearate was found to be insoluble in any ordinary sol- 

 vent, but the oleate is soluble in benzol, gasoline, carbon tetra- 

 chloride, turpentine, and various oils. The solution of copper 

 oleate in benzol or gasoline penetrates cotton lines readily, and 

 on evaporating, leaves a uniform deposit of copper oleate on, and 

 possibly in, the fibres. 



One of the difficulties at first encountered with copper soap 

 was its tendency to creep to the surface of the line on drying. 

 It was found, however, that the presence of a small amount of 

 non-volatile mineral oil in the benzol solution serves largely to 

 prevent this creeping. When gasoline is used as a solvent, the 

 small quantity of a fraction of high boiling point present helps to 

 prevent this creeping. 



METHODS USED AND PRESERVATIVES STUDIED IN PRESENT 

 EXPERIMENTS. 

 The work so far described was of a preliminary nature; it 



