9 in the United States. 15 
Art. I].—On the Magnetical Dip in the United States ; by 
Joun Locke, M. D., Prof. Chem. and Pharm., in the Medical 
College of Ohio. 
TO THE EDITORS, 
In reply to the article by Prof. Loomis, in Vol. xxxrx of your 
Journal, permit me to observe by way of narration, that the cor- 
respondence between him and myself, originated in the following 
manner. Prof. Loomis being about to republish a chart of the 
magnetism of the United States, requested as a favor, that I 
would furnish him with some of the results of my observations. | 
I cheerfully complied, by sending him the principal ones. When 
his paper appeared, I saw my results marked “in error” to a con- 
siderable amount. Upon examination, I found that the expres- 
sion ‘in error,” meant merely that the observations did not agree 
with an assumED HyPoTHEsis, by the amount noted. I objected to 
this mode of expressing differences, chiefly because it would mis- 
lead popular readers, and with them would do me discredit as an ob- 
server. My paper on that subject in your Journal, Vol. ae 
will be found at every point, complimentary to Prof. Loomis. The 
reader will please to observe that I have not made a single ren 
on Prof. L.’s own observations. I should have felt great delica 3 
especially in undertaking to criticise or point out any errors or 
faults which I might suppose attended them. This i6°0 task ~ 
which I conceive belongs to the observer himself, after he shall _ 
have made all of the comparisons necessary for the labor, and 
shall have ascertained all of the circumstances possible, which 
may explain the real or apparent anomalies. A second, per- 
son may misapprehend many things which the observer himself 
could have rectified, or explained instantly, and may thus pro- 
duce injury of reputation, and of feeling, by hastily publishing to 
the world, a supposed discovery of errors, where none ever ex- 
isted. Ihave merely sought that my own observations should 
be presented to the popular reader in such a manner that he 
should not misapprehend them to my discredit. Prof. Loomis 
will certainly grant that the notes of an unfinished labor of mine 
were communicated to him, with a tacit understanding to that 
effect. I did not in my last paper, presume that he had intended 
to use them in any other manner, than that which haw be to 
my honor. 
