This section is from the book "Hints On Household Taste In Furniture, Upholstery And Other Details", by Charles L. Eastlake. Also available from Amazon: Hints on Household Taste in Furniture, Upholstery and Other Details.
Unfortunately for the interests of Art, a taste grew up in the eighteenth century for the imitation of crystal. Now, without entering into scientific details, it is sufficient to remember that glass is formed by the combination of silica (sand or flint) with an alkali, or with oxide of lead. These, on the application of heat, fuse into colourless transparent liquids, and finally cool into hard brittle solids, having an amorphous or non-crystalline character. It is true that under rare conditions, similar to those which result, for instance, in the production of what is called Reaumur's porcelain, the formation of crystals may be determined by the application of heat lower than that necessary to effect the perfect fusion of the glass. But then that material which is opaque in substance, has become actually devitrified, and can hardly be called glass at all. Any attempt, therefore to give ordinary glass, such as is manufactured for drinking vessels, etc, the appearance of cut crystal, is to treat it in a manner foreign to its real nature. Our manufacturers not only aimed at this, but, by the employment of minium (red lead) in large quantities, they endeavoured to invest their table glass with a peculiar brightness which it is almost impossible to attain without that ingredient. In this way, however, they lost two important qualities of the old material, viz., lightness and ductility. It cooled during manufacture much more rapidly than before, leaving little or no time for that delicate hand-work which we recognise in the graceful forms and fantastic ornament of Venetian glass; but these defects have until lately been almost regarded in the light of advantages.
In the manufacture of table glass, some fifty years ago, great angularity of form, lumpy ornament, deep incisions, and solidity of material were the chief characteristics of its design. Now all these are directly opposed to the natural properties of glass, which, in a state of fusion, is capable of being blown and twisted into the most light and elegant forms, which though apparently fragile may last for ages afterwards if handled with ordinary care. Old Venetian glass was of this kind; and, elaborately decorated as many of its examples are, the lightness of their weight is extraordinary. Combined with this lightness we find a peculiar elasticity of material which renders the glass hardly less brittle than the more solid-looking examples of our own time.
Now it is well to bear in mind what constitutes the material beauty of glass. If it is to be perfectly colourless and clear as water, but heavy withal, then modern English glass is the best that has been produced. But to the eye of an artist the delicate gradations of natural colour, the slight imperfections and streakiness of old glass, render it infinitely more attractive than a purity of texture which has nothing but its clearness to recommend it, and which can only be acquired by a sacrifice of more precious qualities. For the simple transmission of light through the best piece of flint glass that could be manufactured is of small value compared with the mellow and often jewel-like effect produced in the design of a Venetian beaker. In addition to this it must be remembered that table glass, to be made spotless in substance, must also be made heavy. It is the red lead employed in its manufacture which gives our glass its weight as well as its artificial lustre. Under these conditions of material, our manufacturers had recourse to moulding, pressing, cutting, and engraving - modes of decoration which, as they were once practised, reduced the workman to a mere machine, and left him to think of nothing but making his tumblers accurately round and his goblets perfectly symmetrical.
One of the conditions of aesthetic taste seems to be that in civilised life it shall revolve in cycles; and whether or not we may attribute the change to a certain impetus which our art manufacturers received through the Great Exhibition of 1851, it is certain that after that date a great modification took place in the design of English table glass. People began to discover that the round bulbous form of decanter was a more pleasant object to look at than the rigid outline of a pseudo-crystal pint-pot carved and chopped about into unmeaning grooves and planes. The reversed and truncated cone, which served our grandfathers as a model for wine-glasses, gradually disappeared before the lily and crocus-shaped bowls, from which we now sip our sherry and Bordeaux. Champagne had formerly been drunk from tall and narrow glasses, which required to be tossed aloft before they could be emptied. It is now a broad and shallow tazza which sparkles with the vintage of Epernay. For some years past the forms of our goblets and water-bottles have been gradually improving; many artistic varieties of the material have appeared, and the style of decoration employed, especially with engraved glass, is very superior to what it used to be. Some English manufacturers have even endeavoured to reproduce the most familiar types of old Venetian glass. But these imitations have hitherto been carried out in the letter rather than in the spirit of ancient work. There has been a too evident striving after perfect accuracy of form, and that ignoble neatness of execution which is fatal to the vigour of good design. If the workman is directing his energies to make a round dish mathematically correct in outline, or the opposite profiles of a jug match each other with absolute precision, he cannot be expected to work with the free hand of an artist. So our table glass was very bright, very accurately shaped, often very nicely engraved; but, on the other hand, very heavy, seldom otherwise than formal in contour, and generally unpicturesque.
In short, we have gradually given up the vigour of design, gradation of tone, brilliance of colour, as well as the lightness and elasticity of old glass, simply for the sake of getting two sides of a decanter exactly alike, and being able to see each other clearly through the centre !