sam 
163 
as determined by Dumas; and the most probable rational 
formula he stated to be 
1K +3 (1 + cz). 
Calculating from this formula, its composition would be 
Iodide of potassium . 12.26 
Todine 1... . . 28.08 
Oilofcinnamon . . 59.66 
100. 
This compound he considered interesting under many 
points of view ; in consequence of its complexity, the peculi- 
arities of its properties, and its presenting a case of in- 
compatibility which had not been previously suspected. 
Also, as suggesting means which would probably lead to 
the production of an entire new series of substances hav- 
ing an analogous composition. 
Dr, Apjohn stated, that this compound had been brought 
under his notice by Mr. Moore of Anne-street, and that he 
and Mr. Moore had investigated conjointly its properties, 
and the best process for obtaining it. Of the specimen exhi- 
bited to the Academy, sixty-one grains were obtained from a 
single gallon of cinnamon water. 
Professor Lloyd read a paper “ on a Declination Instru- 
ment, made for the Magnetical Observatory of Dublin.” 
The instrument, which was made by Mr. Jones of London, 
was laid upon the table of the Academy. 
The principle employed in this apparatus is the well 
known optical principle of the collimator of Kater. The 
needle is a rectangular bar, twelve inches in length; it is 
provided with three sliding pieces, one of which is at the 
middle of the bar, the other two near the ends. To the for- 
mer is attached the suspension thread; one of the latter car- 
ries an achromatic lens, whose focal length is somewhat less 
than the length ofthe bar; the other, which is to be adjusted 
