ch seem to move them； its animal spirits to the water which impels them； of which the heart is the fountain； while the cavities of the brain are the central office。 Moreover； respiration and other such actions as are natural and usual in the body； and which depend on the course of the spirits； are like the movements of a clock； or a mill； which may be kept up by the ordinary flow of water。〃＇3＇ In such passages as these Descartes anticipates the ideas of physiology of the present time。 He believed that the functions are performed by the various organs of the bodies of animals and men as a mechanism； to which in man was added the soul。 This soul he located in the pineal gland； a degenerate and presumably functionless little organ in the brain。 For years Descartes's idea of the function of this gland was held by many physiologists； and it was only the introduction of modern high…power microscopy that reduced this also to a mere mechanism； and showed that it is apparently the remains of a Cyclopean eye once common to man's remote ancestors。 Descartes was the originator of a theory of the movements of the universe by a mechanical processthe Cartesian theory of vorticeswhich for several decades after its promulgation reigned supreme in science。 It is the ingenuity of this theory； not the truth of its assertions； that still excites admiration； for it has long since been supplanted。 It was certainly the best hitherto advancedthe best 〃that the observations of the age admitted；〃 according to D'Alembert。 According to this theory the infinite universe is full of matter； there being no such thing as a vacuum。 Matter； as Descartes believed； is uniform in character throughout the entire universe； and since motion cannot take place in any part of a space completely filled； without simultaneous movement in all other parts； there are constant more or less circular movements； vortices； or whirlpools of particles； varying； of course； in size and velocity。 As a result of this circular movement the particles of matter tend to become globular from contact with one another。 Two species of matter are thus formed； one larger and globular； which continue their circular motion with a constant tendency to fly from the centre of the axis of rotation； the other composed of the clippings resulting from the grinding process。 These smaller 〃filings〃 from the main bodies； becoming smaller and smaller； gradually lose their velocity and accumulate in the centre of the vortex。 This collection of the smaller matter in the centre of the vortex constitutes the sun or star； while the spherical particles propelled in straight lines from the centre towards the circumference of the vortex produce the phenomenon of light radiating from the central star。 Thus this matter becomes the atmosphere revolving around the accumulation at the centre。 But the small particles being constantly worn away from the revolving spherical particles in the vortex； become entangled in their passage； and when they reach the edge of the inner strata of solar dust they settle upon it and form what we call sun…spots。 These are constantly dissolved and reformed； until sometimes they form a crust round the central nucleus。 As the expansive force of the star diminishes in the course of time； it is encroached upon by neighboring vortices。 If the part of the encroaching star be of a less velocity than the star which it has swept up； it will presently lose its hold； and the smaller star pass out of range； becoming a comet。 But if the velocity of the vortex into which the incrusted star settles be equivalent to that of the surrounded vortex； it will hold it as a captive； still revolving and 〃wrapt in its own firmament。〃 Thus the several planets of our solar system have been captured and held by the sun…vortex； as have the moon and other satellites。 But although these new theories at first created great enthusiasm among all classes of philosophers and scientists； they soon came under the ban of the Church。 While no actual harm came to Descartes himself； his writings were condemned by the Catholic and Protestant churches alike。 The spirit of philosophical inquiry he had engendered； however； lived on； and is largely responsible for modern philosophy。 In many ways the life and works of Leibnitz remind us of Bacon rather than Descartes。 His life was spent in filling high political positions； and his philosophical and scientific writings were by…paths of his fertile mind。 He was a theoretical rather than a practical scientist； his contributions to science being in the nature of philosophical reasonings rather than practical demonstrations。 Had he been able to withdraw from public life and devote himself to science alone； as Descartes did； he would undoubtedly have proved himself equally great as a practical worker。 But during the time of his greatest activity in philosophical fields； between the years 1690 and 1716； he was all the time performing extraordinary active duties in entirely foreign fields。 His work may be regarded； perhaps； as doing for Germany in particular what Bacon's did for England and the rest of the world in general。 Only a comparatively small part of his philosophical writings concern us here。 According to his theory of the ultimate elements of the universe； the entire universe is composed of individual centres； or monads。 To these monads he ascribed numberless qualities by which every phase of nature may be accounted。 They were supposed by him to be percipient； self…acting beings； not under arbitrary control of the deity； and yet God himself was the original monad from which all the rest are generated。 With this conception as a basis； Leibnitz deduced his doctrine of pre…established harmony； whereby the numerous independent substances composing the world are made to form one universe。 He believed that by virtue of an inward energy monads develop themselves spontaneously； each being independent of every other。 In short； each monad is a kind of deity in itselfa microcosm representing all the great features of the macrocosm。 It would be impossible clearly to estimate the precise value of the stimulative influence of these philosophers upon the scientific thought of their time。 There was one way； however； in which their influence was made very tangiblenamely； in the incentive they gave to the foundation of scientific societies。
SCIENTIFIC SOCIETIES At the present time； when the elements of time and distance are practically eliminated in the propagation of news； and when cheap printing has minimized the difficulties of publishing scientific discoveries； it is difficult to understand the isolated position of the scientific investigation of the ages that preceded steam and electricity。 Shut off from the world and completely out of touch with fellow…laborers perhaps only a few miles away； the investigators were naturally seriously handicapped； and inventions and discoveries were not made with the same rapidity that they would undoubtedly have been had the same men been receiving daily； weekly； or monthly communications from fellow…laborers all over the world； as they do to…day。 Neither did they have the advantage of public or semi…public laboratories； where they were brought into contact with other men； from whom to gather fresh trains of thought and receive the stimulus of their successes or failures。 In the natural course of events； however； neighbors who were interested in somewhat similar pursuits； not of the character of the rivalry of trade or commerce； would meet more or less frequently and discuss their progress。 The mutual advantages of such intercourse would be at once appreciated； and it would be but a short step from the casual meeting of two neighborly scientists to the establishment of 〃societies；〃 meeting at fixed times； and composed of members living within reasonable travelling distance。 There would； perhaps； be the weekly or monthly meetings of men in a limited area； and as the natural outgrowth of these little local societies； with frequent meetings； would come the formation of larger societies； meeting less often； where members travelled a considerable distance to attend。 And； finally； with increased facilities for communication and travel； the great international societies of to…day would be producedthe natural outcome of the neighborly meetings of the primitive mediaeval investigators。 In Italy； at about the time of Galileo； several small societies were formed。 One of the most important of these was the Lyncean Society； founded about the year 1611； Galileo himself being a member。 This society was succeeded by the Accademia del Cimento； at Florence； in 1657； which for a time flourished； with such a famous scientist as Torricelli as one of its members。 In England an impetus seems to have been given by Sir Francis Bacon's writings in criticism and censure of the systern of teaching in colleges。 It is supposed that his suggestions as to what should be the aims of a scientific society led eventually to the establishment of the Royal Society。 He pointed out how little had really been accomplished by the existing institutions of learning in advancing science； and asserted that little good could ever come from them while their methods of teaching remained unchanged。 He contended that the sys