1817.) during the Year 1816. . 1 
tion, no decomposition took place. But if either of them contained 
water of crystallization, they in that case mutually decomposed 
each other. When, after the trituration, a liquid capable of dissolving 
any of the constituents is poured on, decomposition takes place. It 
would appear from these experiments that the water of crystalliza- 
tion, though solid, still continues to exert its solvent powers. 
2. Structure ef Solid Bodies.—A very curious and important 
paper, by Mr. Daniell, has been published in the Journal of the 
Royal Institution (i. 24), which throws much new light upon the 
structure of solid bodies. If a lump of alum, or borax, or of 
nitre, be immersed in a vessel of water, and left at rest for three or 
four weeks, the solution will be found to have gone unequally on ; 
the uppermost portion will be found most wasted, and the under- 
most least; so that the undissolved part of these salts will have 
assumed a conical form. The lower part of these bodies, after this 
treatment, will be found embossed over with numerous crystalline 
forms. These in alum are octahedrons, or figures formed by diffe- 
rent sections of the aluminous octahedron. In borax they are frag- 
ments of eight-sided prisms, and soon. Mr. Daniell has shown in 
a satisfactory way that these embossments are not formed by the 
crystallization of that portion of the salt which has been dissolved 5 
but that they are brought into view by the unequal solution of the 
lump of salt subjected to the action of the water. Hence it follows 
that all these apparently amorphous masses are in reality composed 
of crystals, though such a structure cannot be distinguished by the 
eye previous to this natural dissection of it. The same crystalline 
structure was developed when carbonate of lime, carbonate of 
strontian, and carbonate of barytes, were slowly acted on by 
vinegar. Bismuth, antimony, and nickel, treated with very dilute 
nitric acid, likewise exhibited a crystallized structure. From these 
experiments we may infer, with considerable probability, that the 
structure of most bodies is in reality crystallized, even when they 
appear amorphous. If this mode of natural dissection could be 
applied to minerals in general, it would greatly extend the Hauyan 
method, and remove most of the objections to which it is at present 
exposed. 
Mr. Daniell terminates his paper by an ingenious examination of 
the structure of crystals, and shows that Dr. Wollaston’s hypothesis, 
that the integrant particles of bodies are spherical or spheroidal, will 
alone agree accurately with all the phenomena. 
$8. Anomaly in Affinity—Though chemists have long been 
aware that almost all the phenomena of their science depend upon 
what is called affinity, or upon the attractions which exist between 
the atoms of different bodies, no progress whatever has yet been 
made in measuring the intensity of these forces, It was early laid 
down as an axiom that bodies having an affinity for each other are 
attracted each by a specific force which varies according to the 
bedy, and that when two bodies, a and J, are united, if a third 
