ON THE ACTION OF AIR AND WATER UPON IRON. 273 
“kept just covered with water, or between ‘‘ wet and dry,” a 
series of new experiments have been recently arranged, contain- 
ing specimens of cast and wrought iron, freely exposed to all the 
atmospheric influences, at Dublin. These are coordinate with 
all the experiments, whose first results of submersion are now 
given, and will connect the action of water containing air and 
carbonic acid on iron with that of air holding water and car- 
bonic acid in suspension, &c. ; and, as the meteorological regis- 
ters of Dublin are tolerably perfect, will be hereafter comparable 
with any such made in another locality. The data of this set of 
"experiments may await the publication of a third report, and be 
given along with the results. 
_ 282. Inconcluding this second report upon a subject in which 
I feel a lively interest, and the practical bearing of which needs 
‘no further evidence than the multitude of patents, whether good 
or bad, for inventions intended to preserve iron, &c., which have 
‘been obtained since the publication of the first report, and in 
“retracing the ground already gone over, I must regret the many 
imperfections and omissions, which I might have been enabled to 
avoid, could I have devoted more time to these researches. That 
learned otium, however, so necessary to successful experimental 
“study, is denied to those who, like myself, find every day to come 
preoccupied with the unavoidable duties of a laborious profession. 
Hence, most of these experiments have been made and recorded 
in hours stolen from rest, or, with greater difficulty, from busi- 
ness. 
_ Ihave to thank many individuals for specimens of iron, &c. 
N various conditions, and especially my young friend Mr. 
Charles Scanlan, for his valuable assistance in taking great 
numbers of specific gravities. 
