/ 
184 Prof. Lovering on the American Prime Meridian. 
III. ae 
Rav, Aes ee TS 42-95 
SrO, A, ne ea Se 3650 ~ 
000, Ao ge ees ee ERO 3563 + 
MgO, A, 712 35:18 = 
The above results led to the conviction that all the attributes 
of these metallic bases and their compounds would probably be 
found intense in the order of their atomic weights, a conviction 
which I expressed after presenting a summary of the foregoing 
results, to the meeting of the American Association in 1847. 
I then projected the scheme of decomposing the several 
salts of these bases by transmitting steam over them while sub- 
jected to heat. Circumstances prevented my realizing this inten- 
tion, and in the following year, Mr. Tilghman of Philadelphia, to 
whom my researches could not have been known, as they had 
not been published, announced the results of a series of most 
important experiments—under the head of ‘* Decomposing power 
of water at high temperatures.”* ioe 
Mr. Tilghman found that, while a moderate heat was required 
to decompose sulphate of magnesia with the aid of steam, a higher 
one was necessary for sulphate of lime, a still higher one for sul- 
phate of strontia, and the highest of all for sulphate of baryta. 
‘Thus, their susceptibility to decomposition is in the order of 
their solubility, viz.— 
1. MgO, SO, S.  BeO, e,. 
2. Ca0,8O, 4.  BaO,SO, 
This research fulfilled my expectations, and it would seem 
that there can be little hazard in considering the above facts as 
7 soe of a natural law applying to the group of the alkaline 
earths. 
Art. XXI.—On the American Prime Meridian ; by Professor 
J. Lovertne, of Harvard University. 
As extensive circulation has been given in the pages of this 
valuable Journal and otherwise to the views and arguments of 
those who advocate the adoption of an American prime merid- 
jan, it is incumbent on those who entertain serious objections to 
this important measure to state them fully and frankly; and, 1 
possible, in season to prevent the consummation of a change 
which they consider uncalled for by the necessities of science and 
( iS to commerce. The remarks which I propose to make, 
at this time, are substantially the same as were prepared in reply 
* Chem, Gaz., 1848, p. 181. 
