364 Mr. Charles Tomlinsoris 



by the addition of corresponding sulphurets, previous to the 

 precipitation of the cyanogen by a solution of nitrate of 

 silver ; for this method of estimating the cyanogen, I am 

 indebted to Dr. Turner ; most metallic salts are precipi- 

 tated by the solutions of these salts; the crystals of these 

 salts decrepitate strongly when heated, are decomposed 

 and give off cyanogen gas together with nitrogen ; all these 

 salts crystallize in colourless, transparent octohedrons, except 

 the hydrargyro-cyanuret of strontium, which crystallizes in 

 4-sided prisms. 



I remain yours truly, 



George Henry Jackson. 



30, Church-street, Sjntalfields, March 26th, 1836. 



Article VI. 



Experiments and Observations on Visible Vibration. By 

 Charles Tomlinson, Esq. 



{Continued from page 200.) 



95. In the details which have been already given respect- 

 ing the nodal divisions of glass vessels during vibration, 

 and the effects produced by those vibrations on the con- 

 tained fluids, goblet-shaped glasses were, in most instances, 

 the subject of experiment, but we have found that conical 

 glasses, besides confirming most of the conclusions drawn 

 from the phenomena of the first-mentioned vessels, afford 

 facilities for observing many additional facts with respect 

 to nodal division, and at the same time produce new and 

 interesting sets of acoustical figures, some of which it is 

 the object of the present paper to introduce and describe. 



96. When a goblet is about two-thirds filled with water, 

 (coloured water should be employed), and the fundamental 

 note produced by means of a bow drawn against the edge, 

 the nodes are indicated by the tranquillity of the water at 

 certain equidistant points, while the centre of each vibrating 

 arc becomes a centre of vibration, and a pleasing figure 

 composed of fans 4, 6, or 8 in number, (and I now obtain 

 as many as 10, or 12,) dependent on the dimensions of the 

 vessel, but chiefly on the pitch of the note produced, is the 



