246 Scientific Labors and Character of 



the action of sea water. All the facilities for trying these experiments 

 on a large scale, were afforded him by the government, at the mag- 

 nificent naval establishments at Chatham and Portsmouth ; and the 

 results promised to provide a complete remedy for the evil under which 

 the navy and commerce of Great Britain had suffered so severely. 

 But a consequence which ought to follow in accordance with the hy- 

 pothesis, and which the author had anticipated, (though not to the 

 extent it occurred,) has limited, if not entirely subverted the practical 

 utility of the discovery. The copper sheathing, rendered artificial- 

 ly negative, acquires the power of attracting all those ingredients 

 of sea water, which are naturally positive, as lime and magne- 

 sia. These form a crust on the surface of the copper to which sea- 

 weeds and shell fish adhere, which in long voyages create an imped- 

 iment, that is paramount to the advantages derived from the protec- 

 tion of the copper from corrosion. Although an unexpected conse- 

 quence has limited, or at least for the present embarrassed, the prac- 

 tical applications of this discovery, yet the object sought for, namely, 

 to protect copper sheathing from corrosion by sea tvater, was fairly 

 and fully attained ; and the philosophical process which conducted 

 to the discovery, was complete and perfect, like that which led to the 

 invention of the safety lamp. 



We have watched this bright orb in its ascent through an uncloud- 

 ed and glorious morning, and have traced its radiant path as it moved 

 along its zenith ; but we are now pained to behold it suddenly ar- 

 rested, and in a moment withdrawn forever from our gaze. We 

 have learned, that from the year 1827, the health of Sir Humphry 

 began to decline, and that after many months of severe and danger- 

 ous illness,* he had recovered so far as to be able to resort to his fa- 

 vorite climate in the south, but still led the life of an invalid, until a 

 sudden death released him from his sufferings. We presume he al- 

 ludes to himself in one of the concluding sentences of his last beauti- 

 ful little work, Salmonia, where he makes one of his characters say, 

 "Ah! could I recover any of that freshness of mind, which I pos- 

 sessed at twenty five, and which, like the dew of the morning, cov- 

 ered all objects, and nourished all things that grew, and in which 

 they were more beautiful even than in sunshine, what would I not 

 give ! — All that I have gained in an active and not unprofitalile 

 life."t 



* Salmonia, p. v, I lb. 271. 



