48 
CHEMICAL TRUTH. 
assignable to words according to the sense in which they are 
used; whether in a scientific, a practical, or commercial sense, 
&c., the Babel of theoretical hypothesis may lead to a mutual 
mystification between the witnesses, or there may be a differ- 
ence of opinion among authorities in the absence of any 
tangible means of proof or demonstration. In the case 
reported at some length in our last number, in which the 
question hinged on the meaning of the term coal, five Profes- 
sors of Chemistiy, three Professors of Mineralogy, a Micro- 
scopist, three Geologists, and eight other witnesses practically 
acquainted with mining operations, swore that in their opinion 
a certain mineral product was not coal. Nine Professors of 
Chemistry, four professors of Botany and the allied sciences, 
and sixteen other practical witnesses conversant with geology 
and mining, pronounced it to be coal. For the purpose of 
the trial nearly all this display of science was wasted and mis- 
placed, as the jury were at last thrown on their own resources ; 
in other words, they took a common-sense view of the case. 
The defendants took the lease of the mine with a view of 
obtaining gas-coal. They found a substance known in the 
locality by that name, answering the purpose required, in 
every respect what they wanted, and what they expected to 
find. On the same principle, a quibble might be raised 
respecting the meaning of the term blacklead, and an action 
might be brought to vitiate a contract on the ground that it 
contained no lead. The gravamen of the contention in the 
coal case had no reference to the quality of the material, but 
the action arose out of the fact that the quantity found 
exceeded the expectations of the plaintiffs. If the quantity 
had been inconsiderable, its identity would not have been 
called in question ; but the large returns made it worth while 
to call in the aid of science to cancel a lease on the strength 
of a technical definition based upon chemical analysis. 
A remarkable case of this kind — that of Severn v. the 
Imperial Insurance Company — is reported at length in the 
Quarterly Journal of the Royal Institution for 1821. The plain- 
tiff was a sugar-refiner, who had insured his premises, &c., 
with the defendants for £70,000. The premises having been 
destroyed by fire, the defendants refused to make good the 
loss, in consequence of heated oil, circulating through a pipe 
in the sugar-pan, having been used for boiling the sugar; and 
the principal question at issue w as, w r hether the oil, at the 
temperature at which it was used, emitted inflammable gases, 
so as to render the process dangerous. The case was tried 
in the Court of Common Pleas, at Guildhall, before Lord 
Chief Justice Dallas, who, in summing up, made the following 
