There is, however, in this connection, one point worth notice. It is impossible to prepare a workable glass from quartz and alkali alone; the presence of a certain quantity of lime is essential. Now in the forest glass—the _verre de fougère_—sufficient lime (or equivalent bases) is provided by the impurities in the crude potash employed; but this is no longer the case when the more carefully prepared Oriental or Spanish soda takes its place: it is now necessary to supply additional lime. It is not impossible that the secret of the shrewd Italians may have lain in this direction. When speaking of the mediæval glass of France, I have brought forward some evidence to show that, by the fourteenth century at least, vessels of glass must have been produced in large quantities for domestic use. This of course was, without exception, _verre de fougère_, essentially the glass of the people, which for long was little influenced by the new Italian methods. It was this glass chiefly that was hawked round the country by itinerant vendors. Their cry was well known in Paris—‘_Gentils verres, verres jolis—à deux liards les verres de pierre!_’ Others, as in old days at Rome (see the quotation from Martial on p. 82, note), collected broken glass to the cry of ‘_Chambrières, regardez-y!—Voirre cassez, Voirre cassez!_’[169] Bernard Palissy, writing towards the end of the sixteenth century, gives but a mean idea not only of the hawkers, but of the makers of glass in his day:—‘Je te prie, considère un peu les verres qui, pour avoir esté trop communs entre les hommes, sont devenuz à un prix si vil que la plupart de ceux qui les font vivent plus méchaniquement que ne font les crocheteurs de Paris ... et ces verres sont venduz et criez, par les villages, par ceux mêmes qui crient les vieux chapeaux et les vieilles ferrailles’ (quoted by Gerspach, p. 193). It was only when the secrets of the pure _cristallo_ and the application of enamels were introduced from Italy that glass began to take a more honourable position in France. We cannot safely trace back the foreign influence to an earlier date than the middle of the fifteenth century, and it was not brought into full play till just a century later.