Dr Ogden mi Saline Crystallization. 319 



I never could calculate with any certainty on the phenomena 

 which these experiments would present. They were often total 

 failures, and it was only by frequent repetition of them that 

 their peculiarities could be observed. The following is an in- 

 stance of the irregularities I met with. 



^^14; 'A pound of crystallized acetate of soda was fused in its 

 water of crystallization, and poured into a clean glass retort. 

 Six hours afterwards, it was cold and perfectly fluid, with the 

 exception of a mass of crystals about the size of a hazel nut, 

 which lay at the bottom of the retort, and a iew smaller masses 

 which were floating in the liquid. It was several times shaken 

 without its shewing any tendency to crystallize. A small cry- 

 stal of the same salt being then dropped in, the entire mass be- 

 came solid in a few seconds. The evolution of sensible heat 

 which attends the transition from the liquid to the solid state, 

 was in this case very considerable. 



15. Sulphuric acid sufficient to decompose the acetate of soda 

 was then added, and the acetic acid was drawn off' by distilla- 

 tion. Water was poured on the residuary sulphate of soda 

 when cold. The next day about two-thirds of the salt had dis^ 

 solved ; but on attempting to pour it out of the retort, it sud- 

 denly crystallized, and became a semifluid mass. 



SUKDERLAND. 



On the Magnitude of the Ultimate Particles of Bodies ; In- 

 fusory Animals not formed immediately Jrom Dead Matter ; 

 i^xtracyrdinary Mlmiteness of the Infusoria ; Improved Ar- 

 rangement of the hfusoria ; Marvellous Multiplication of 

 the Infusoria ; Estimate of the relative value of the Micros- 

 copes of Chevalier^ Ploessel, and Schiek. By Prof. C. G. 

 JEhrenberg of Berlin. 



Magnitude of Ultimate • Particles. — Within these few years, 

 the atomists have become pretty confident in their doctrines re- 

 lating to the minute particles of bodies. They have not rested 

 satisfied with viewing atoms as ideal unities of an infinite degree 

 of minuteness, but have sought for approximative numerical ex- 



