410 Mr. Snow Harris on the Electrical Discharge 



in the way of objection to the fixing conductors in ships' masts, 

 and prove in the most conclusive manner the protecting 

 power of such conductors : his statement, therefore, that " de- 

 structive lateral discharges will always take place when the 

 vicinal bodies are capacious and near the primitive conductor 

 or to any of its metallic appendages," is clearly fallacious. 



36. It is allowed by writers on inductive science, that we 

 wander from the true path of philosophical inquiry, and take 

 up that of assumption and conjecture,directW we cease to verify 

 our principles by an appeal to facts. In order to arrive at a 

 general law of nature, it is requisite to examine carefully a 

 great number of facts bearing directly on the question at issue, 

 and show, that the principle we assume is common to them 

 all ; for if in any case the assumed principle is decidedly ne- 

 gatived, it is at least a powerful exception ; and it mayhe. suf- 

 ficient to overturn our whole theory. 



If such exceptions are numerous, any theory which cannot 

 include them is decidedly untenable. 



It has been well observed by Abercrombie * that in 

 deducing a general principle, " when the deduction is made 

 from a full examination of all the individual cases, and 

 the general fact shown to apply to them all, this is truth ; 

 when it is deduced from a small number of observations and 

 extended to others to which it does not apply^ this is false- 

 hood." 



37. In applying these principles, we find Mr. Sturgeon's 

 assumed lateral explosion decidedly negatived in all the 

 cases just cited, since we do not find any such occur in the 

 passage of heavy discharges of lightning along the masts, 

 &c. ; we do not find, as asserted by him, anything like elec- 

 trical waves produced by the discharge through a conductor 

 situated close to the magazine. Thus in the case of the Hy- 

 acinth, No. 1. the copper pump, de, fig. 1, was a conductor 

 near the after magazine. Yet the electric shock, in passing 

 down this and through the ship's side, did not cause "intense 

 sparks among the powder barrels, whose metallic linings and 

 hoops reciprocally interchange them f-" 



38. Again, we do not find in the passage of a dense explosion 

 of lightning that the sailors are necessarily subjected to la- 

 teral discharge, since in the case of the Snake, it may be ob- 

 served that a seaman aloft on the cross-trees did not experi- 

 ence any sensatioji whatever, although the top-gallant mast 

 was shivered, and a terrific shock darted from the heel of it 

 to the chain topsail tye. Now if Mr. Sturgeon's views were 



* On the Intellectual Powers. t Sturgeon's Memoir. 



