CHAPTER FOUR THE REVELATION OF THE MICROSCOPE Athanasius Kircher holds an important place in the history of medi- cine, for indeed, he was one of the earliest true microscopists. Perhaps it will entail an irksome textbook approach, but any attempt to come to grips with Kircher’s medical significance without a knowledge of his stature and development as a microscopist would be ineffective. This in turn will involve filling out the background history of the microscope and of its users, from the earliest days until shortly after Kircher. The microscopes used by Kircher and on which he based his valu- able contributions to European medical thought were of two kinds, simple and compound. Simple Microscopes Both Euclid and Ptolemy were aware of the principles of refracted light. Plato tells us of spheres of glass filled with water and used as cau- teries, a piece of information echoed both by Seneca in classical Rome and by the Asian Kalidasa in the Sahuntala of fifth-century ad. This knowledge was lost to Europe until the Arab Alhazen (d. 1038) suc- ceeded in passing it on. Both Roger Bacon1 and the early Italian scien- tist Vitello knew of and wrote about Alhazen’s works.2 Our knowledge of the first invention of spectacles and thereby early attempts at the production of optical lenses is obscure but this is usually attributed to Salvino d’Amarto degli Amati of Florence and equally to Alessandrino de Spina of Pisa near the end of the thirteenth century. The first known mention of such crude prototypes occurs in the Lilium medicinae of Bernard de Gordan, who died in 1307. The mediaeval alchemists were not long in imitating the gem cutters of antiquity in using water-filled glass spheres for magnification, but 1 See Bridges, The ‘Opus Major’ of R. Bacon, pp. lxixff. 2 Alhazen was translated into Latin by Gerard of Lemona as Thesaurus opticae, c. 1542. A second edition, combined with the Optica of V. Vitello, appeared in 1572, thus in Vitellionis perspectivae. 106 chapter four the first real advance was made, characteristically, by Leonardo da Vinci (1452–1519), who was closely followed by the abbot Francesco Maurolico (1449–1572)3 and the natural scientist Giambattista Porta. In England, Leonard Diggs and his son Thomas4 were aware of the vir- tues of concave and convex lenses, and they in turn were followed by Thomas Mouffet in France and Kepler in Germany.5 In 1637 in France, René Descartes, in his curious ‘Dioptrique’,6 published an elaborate form of unilenticular microscope which appeared to resemble a mix- ture of the astrolabe and an astronomical telescope. Descartes’ version was illustrated in 1646 in Athanasius Kircher’s treatise Ars magna lucis et umbrae in a chapter entitled ‘De mira rerum naturalium constitu- tione per microscopium’ (‘Concerning the wonderful constitution of things in Nature as seen through the microscope’), which was to enjoy a brief European reputation before subsequent technical advances made it obsolete. In simple but historic words, Kircher introduces his microscope: ‘This is that divine science of optics which brings out from the deepest darkness into admirable light what has been hidden. Certainly, until now, it has been believed of many bodies that they were without all life and soul, but now they are shown by dioptics to be alive’. He goes on to ask, in a wondering voice: ‘Who could have believed that vinegar and milk teem with an innumerable multitude of worms, unless the art of the microscope in these last times had shown it to be so, to the greatest wonder of everyone?’ He makes a few simple observations and asks, with the air of a proud father revealing his son to the world: ‘What else does a flea look like but a locust without wings? What else does a mite look like but a shaggy bear?’ A significant observation is yet to come as Kircher enumerates his amazing discoveries: he talks of ‘the worm-affected blood of those suffering fever’ and the ‘minute organisms in putrifying material’.7 In this context Kircher describes two of his microscopes. The first consists simply of a hollow tube, A B. At B is the lens (which is obscured in Kircher’s appended illustra- tion), while at A there is merely a plain glass disc on which the object 3 Maurolico, Photismi de lumine et umbra, etc. 4 In their Pantometria of 1571. 5 See Kepler, Astronomicae pars optica and Dioptrice. 6 I.e., in the ninth discourse of his Discours de la méthode. 7 Ars magna, pp. 831, 833 (quotations). Kircher’s observed and recorded ‘minima animalcula’ here clearly precede by some 30 years before Anton van Leenwenhoek’s ‘clejne bestjes’ (see infra)..