1078 Experiments and Papers, [No. 144, 



ing the extent of the former, and of preventing as much as possible the 

 latter of these two great objections to the general employment of iron 

 as a material for the purpose of Naval Architecture. 



My appointment as Surgeon to the Phlegethon, one of the Steam 

 Boats above alluded to, enabled me to make some observations upon 

 the subject, not perhaps of any great value, but such as they are, I 

 respectfully communicate them, with one or two suggestions resulting 

 therefrom, which have at least this recommendation of being ap- 

 proved by Captain Cleaveland himself, particularly interested in the 

 enquiry. 



Knowing, however, that the Indian Government, with its usual energy 

 and desire for the public good, has already instituted an investigation 

 of the properties of iron, conducted by some of the most scientific men 

 in Calcutta, I enter the discussion with diffidence, especially, as perhaps 

 my views and recommendations upon the subject may differ very con- 

 siderably from theirs, the result of long-conducted, and of course very 

 accurate experiments. Scholastic leisure too, as it admits of an intimate 

 knowledge with the whole circle of the sciences, or in lieu of that, of 

 an immediate reference to the best authorities, is an advantage I have 

 not possessed ; but as an equivalent, and an apology also for intruding 

 my remarks, I offer a constant residence and continual experience for 

 above 18 months on board Iron Vessels, where opportunity was daily 

 afforded me of observing and recording those facts, I conceived to be 

 best suited for the determination of questions such as are now before 

 us. 



In the first place I have been led to believe, that the corrosion or 

 oxydization of iron by sea-water is far from being an evil of that mag- 

 nitude which it has been assumed to be ; and in fact, I consider it to be 

 the natural and only certain remedy to prevent the accumulation of 

 marine animals and their habitations upon the surface of the metal ex- 

 posed to the sea, resembling in this respect the very useful protective 

 influence of the sea-salts on copper sheathing upon wooden vessels 

 against a similar evil. 



As regards the definition of oxydization, which the proper consi- 

 deration of our subject certainly requires, the progress of Chemistry as 

 a popular science, renders it unnecessary for one to enter more fully into 

 details, than merely observing, that by the operation of general law of 



