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Auckland Star, Volume II, Issue 467, 10 July 1871, Page 2

Weekly state of H.M. Gaol, Auckland, for tho week ending July 8: —On remand, 4 males ; awaiting trial, 6males; sentenced to penal servitude, 48 males ; sentenced to hard labour, 82 males, 14 females s sentenced to imprisonment, 1 male i default of bail, 1 male, I^female j debtors, 3 males ; received during the week 19 males, 6 female* j discharged dur« mg thei week, 16 males, 6 femrtwr^Total in gaol, lUmrti,, 15 females, ™~, ' * .'.

The chemical composition of glass is that of mixed silicate of potassium or sodium with silicates of calcium, lead, aluminium, and others. The mixture must be so proportioned that there is not sufficient alkaline silicate present to render the product attackable by water or acids. Silicate of calcium increases the fusibility and also the resistance to the action of water. Silicate of aluminium renders glass less fusible aud less liable to be acted on by water, w bilst the more the potash, lime, or oxide of lead increase, the more fusible and soft the glass becomes. Bottle glass h-.r~~i specific gravity of 2.7 ; its compositio — principally that of a mixed silicate of calcium and aluminium. Ordinary window glass is approximately a mixed silicate of calcium. English crown g'.ass contains silicates of potassium and calcium. English crystal glass is a mixed silicate of potassium and lead. Flint glass has a somewhat similar composition, but with varied proportions. Faraday's heavy glass (specific gravity 5-44) is a silico borate of lead. Glass is coloured red by gold or copper, blue by cobalt, yellow by silver or iron, and green by chromium. The third volume of the Transactions of the ISew Zealand Institute has been distributed to the members, and forms a most valuable addition to every scientific library. The plates are beautifully executed on stone, and the entire preparation of the book is extremely creditable.