370 Miscellanies. 
part with any of its water of combination. For estimating the 
amount of platinum and chlorine, the salt was fused with carbonate 
of potassa, &c., and the platinum, thus obtained, weighed by itself, 
and the chlorine precipitated from the solution by nitrate of silver. 
The quantity of nitric oxide was determined by introducing a por- 
tion of the salt into a graduated tube, inverted over mercury, and de- 
composing it by letting up the requisite proportion of water. 
The mean of a series of experiments, varied in different ways, gave 
Platinum, - - 41.26 per cent. 
Chlorine, - - 43.89 
Nitric oxide, - 4,98 *% 
The above results correspond to five atoms of bichloride of plati- 
num ; five atoms of hydrochloric acid, and two atoms of nitric oxide. 
The water was calculated from the loss, in the analysis, to be equiv- 
alent to ten atoms. 
Respecting the chemical nature of this compound, it may be re- 
garded, either as a chloride of platinum, with a muriate of nitric ox- 
ide, represented by the following formula, (Pt Cl?) 5+[(Cl H)*+ 
(NO? )?]-+- 10 Aq, or as a double chlorosalt, a chloroplatinate of ni- 
trogen, with a chloroplatinate of hydrogen, repeats by the formu- 
la, [(Pt Cl?)?--N Cl? ]? +(Pt Cl? +H Cl) + 
Professor A. D. Bache made a verbal tein in which he 
compared the observations on the magnetic dip by Professor Loomis, 
contained in his paper ordered this evening for publication, with those 
given in a paper by Professor Courtenay and himself, read before the 
Society in 1834, 
The following resolutions i in relation to ‘combined eo obser- 
vations were adopted : 
Resolved, That in the opinion of the American Philosophical So- 
ciety, it is highly desirable that the combined series of magnetic ob- 
servations now in progress under the direction of the British govern- 
ment, should be extended to the United States, by the establishment 
of Magnetic Observatories at suitable places. 
Resolved, That a Committee be appointed, with authority, on be- 
half of the Society, to invite the attention of one of the departments 
of the Government of the United States to the plan for combined 
magnetic observations, a sketch of which was presented in the docu- 
ments from a Committee of the Royal Society of London, and to urge 
co-operation i in the plan as a national undertaking, in every way Wor- 
thy of the United States.* 
ttee were eng and a letter or memorial on the subject dra 
addressed to Hon. J. R. Poinsett, Secretary of War. This Later 
, but as it failed to effect its object at the pro- 
