To obviate this difficulty Felice Fontana of Florence (Saggio del real gabinetto di fisica e di storia naturale, 1 755) first proposed the use of spider webs in micrometers,' but it was not till the attention of Troughton had been directed to the subject by Rittenhouse that the idea was carried into practice.'
The nucleus was definitely recognized in the plant cell by Robert Brown in 1831, but its presence had been previously indicated by various observers and it had been seen by Fontana in some animal cells as early as 1781.
The old castle, at one time the residence of the patriarchs of Aquileia, and now used as a prison, was erected by Giovanni Fontana in 1517 in place of the older one destroyed by an earthquake in 1511.
A map of Italy in the baptistery of St Peter at Rome has occasionally been described as a relief, though it is merely a rude outline map of Italy, by Carlo Fontana (1698), carved into a convex surface.
79 (edition of 1852); Fontana, Monumenta Dominicana, p. 52 (Rome, 16 75); Luke Wadding, Annales Minorum, iii.