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posed of filaments which are found to be joined con-stantly and regularly at an angle of sixty degrees, andwhich, by this angular disposition, occupy a greater vo-lume than if they were parallel. He found the augmen-tation of the volume of water by freezing, in differenttrials, a fourteenth, an eighteenth, a nineteenth, andwhen the water was previously purged of air, only atwenty-fecond part: that ice, even after its formation,continues to expand by cold ; for after water had beenfrozen to some thickness, the fluid part being let out bya hole in the bottom of the vessel, a continuance of thecold made the ice convex ; and a piece of ice, which wasat first only a fourteenth part specifically lighter thanwater, on being exposed some days to the frost, be-came a twelfth part lighter. To this cause he attributesthe bursting of ice on ponds.

Wax, resins and animal fats, made fluid by fire, in-stead of expanding like watery liquors, shrink in theirreturn to solidity ; for solid pieces of the same bodies finkto the bottom of the respective fluids, a proof that thesebodies are more dense in their solid than in their fluidstate. The oils which congeal by cold, as oil olive andthe essential oil of aniseeds, appear also to shrink in theircongelation. Hence, the different dispositions of differentkinds of trees to be burst by, or to resist, strong frosts, areby some attributed to the juir.es, which the ticc aboundswith, being in the one cafe watery, aud in the other resi-nous or oily.

The earthy powders that mingle with water into anuniform paste, exhibit differences, not less stronglymarked, in the affections of their volume by drying. Thecontraction of clay in drying is well known, and allow-ance is made for it by the workmen, in forming modelsor other works of moist clay where any exactness is re-quired in the dimensions. I tried pure clay, and mixturesof it with different proportions of sand, all beaten up

I with