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. 
S6. 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,directly 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 may be 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 alt 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 apyly^ 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, d e, 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 sensation 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. 
