It has been found that, by squeezing a spider, and placing the finger against its papillæ, the liquid of which the thread or silk is made may be drawn out to a great length. M. Reaumur, the rival experimentalist to M. Bon, discovered that the papillæ are formed of an immense number of smaller papillæ, from each of which a minute and distinct thread is spun. He asserted that, with a microscope, he counted as many as seventy distinct fibres proceeding from the papillæ of one spider, and that there were many more threads too minute and numerous to compute. He jumped to a result, however, that is sufficiently astonishing, namely, that a thousand distinct fibres proceed from each papillæ; and there being five large papillæ, that every thread of spider's silk is composed of at least five thousand fibres. In the heat of that enthusiasm, with which the microscope filled speculative minds in the beginning of last century, M. Leuwenhoek ventured to assert that a hundred of the threads of a full-grown spider were not equal to the diameter of one single hair of his beard. This assertion leads to the astounding arithmetical deduction, that if the spider's threads and the philosopher's hair be both round, ten thousand threads are not bigger than such a hair; and, computing the diameter of a thread spun by a young spider as compared with that of an adult spider, four millions of the fibres of a young spider's web do not equal a single hair of M. Leuwenhoek's beard. The enthusiastic experimentalist must have suffered horrible martyrdom under the razor, with such an exaggerated notion of his beard as these calculations must have given him. A clever writer, in Lardner's Cyclopædia notices these measurements, and shows that M. Leuwenhoek went far beyond the limits of reality in his calculation.