Grace K. Babson Collection of Newtonia

The Grace K. Babson Collection of Newtonia was acquired through the efforts of Grace Knight Babson, first wife of Roger Babson, and is the largest source of Isaac Newton materials in the United States. The original 1950 printed catalog is available as a PDF.

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Newton’s Works

The collection includes a library of more than 1,000 volumes of English and foreign language editions of Sir Isaac Newton’s works (many of which are autographed and annotated in Newton’s hand), manuscripts, engravings, artifacts, and other Newton memorabilia, including a death mask that originally belonged to Thomas Jefferson.

A unique feature of the collection is the actual fore-parlour of the last London residence of Newton. Novelist and diarist Frances Burney describes the room as where her parents had entertained many interesting guests during their period of owning the house.

Another unusual piece from the collection is the fifth-generation Newton apple tree grove, which grows on the Babson campus.

The collection is currently on loan to the Huntington Library in San Marino, Calif. From 1994 until November 2006, the collection was housed in The Burndy Library at The Dibner Institute for the History of Science in Cambridge, Mass. The closing of the Burndy Library in 2006 necessitated a move, and the Grace K. Babson Collection of Newtonia followed the Burndy Collections to the Huntington Library.

The Newton Project, hosted by Sussex University, is another excellent effort to make available the scanned works of Newton from sources all around the world.

Origins of the Collection

Grace Babson was the wife of Roger Babson, a well-known figure in the world of finance—the founder and for many years the director of Babson’s Reports. Babson became world famous when he braved the tides of general optimism and predicted the stock market crash of 1929.

Roger Babson often related how his ability as a financial analyst was based on his application of Newton’s Third Law—the law of action and reaction—which he had learned as part of his training in rational mechanics as an undergraduate at Massachusetts Institute of Technology (MIT). His enthusiasm for Newton was increased by his awareness that Newton had combined the practical with the theoretical. For example, in addition to exploring by experiment the phenomena of light and color, Newton adapted his principles to the design and construction of a new instrument: the reflecting telescope.

Babson was able to create a monument to Newton when he purchased and re-erected the fore-parlour of Newton’s last London residence, which he found had been preserved when Newton’s home was razed. This room is now part of the Horn Library at Babson College.

Grace Babson shared her husband’s enthusiasm for Isaac Newton, and for many years collected the various editions and translations of Newton’s writings, together with Newton’s manuscripts and commentaries on his work or discussions of his ideas. During the first half of the 20th century, book collectors displayed relatively little interest in the writings of scientists, so Grace Babson was able to amass her collection of Newtoniana on a scale that would be virtually impossible to duplicate today. The collection remains a monument to her insight and wisdom.

The means that allowed Grace Babson to assemble the collection had its roots, appropriately enough, in the work of Newton. At the suggestion of Professor George F. Swain of MIT, she and her husband devised the Babson Chart.

This tool for market analysis and forecast was a unique application of Newton’s third law of action and reaction to the field of economics, based on the Babsons’ belief that this principle governs the field of human relations as well as that of physics. On this Newtonian foundation, they built a sizable fortune through investments and market speculation.

Financial success made it possible for Grace Babson to search out Newtoniana on a grand scale. Her growing collection was given to Babson in 1939, and she continued to add to the collection during the next two decades. At her death in 1956, Grace Babson bequeathed the last of her collection to what is now Babson College, where it remained until 1995, when it was placed in the permanent collection at the Burndy Library of the Dibner Institute for the History of Science and Technology, at MIT—the alma mater of Roger Babson. In 2006, the Burndy Library and Dibner Institute left MIT for the Huntington Library in California. The Grace K. Babson Collection of the Works of Sir Isaac Newton joined the Burndy Collections at the Huntington.

Description of the Collection

The Grace K. Babson Collection includes all of the editions, translations, and major commentaries of both of Newton’s most important works—the Principia and Opticks—that appeared during his lifetime, as well as those of the succeeding two centuries. There also are editions and translations of Newton’s System of the World and Optical Lectures, and his several mathematical publications. Many of these appear in variant issues of the greatest rarity and value.

The collection also includes the printed editions of Newton’s writings on ancient chronology and religious subjects as well as books by other authors interpreting, explaining, defending, and criticizing Newton. The intellectual intensity of the time comes alive in these works, which include titles by nearly every great scientific and mathematical name of the period: Kepler and Descartes; Leibniz, Huygens, and Boyle; Maclaurin, Saunderson, Halley, Keill, Gregory—all make an appearance.

The collection includes several volumes with annotations by Newton, among which two in particular stand out. A first edition of the Principia contains annotations made both by Newton and by Sir Edmond Halley, who was editor and reviewer for the 1687 edition. The annotations include corrections and alterations, many of which appear in the second and third editions of the book. Also of great note is a copy of the second edition of the Opticks (London, 1717), which bears several long annotations in Newton’s hand.

The Grace K. Babson Collection contains approximately 60 manuscript items, most of which come from the Portsmouth sale (see Online Newton Project). The Babson manuscripts represent nearly the full range of Newton’s activities; they include correspondence, calculations, elaborate alchemical and theological musings, and bookkeeping receipts. About 40 are in Newton’s hand, often signed, including a beautifully illustrated alchemical text picturing the Philosopher’s Stone. Another, the 26-page “Praxis,” likely written in 1693, during a time of extreme emotional stress, is arguably Newton’s most important alchemical manuscript. The most outstanding single item is certainly the 84-page autograph manuscript titled “A Treatise or Remarks on Solomon’s Temple,” with six sketches drawn by Newton, showing plans, charts, and architectural details of the temple. The size of Solomon’s Temple was a prominent puzzle in theological inquiry at the turn of the 18th century; figures as varied as the scientist Robert Hooke and the architect Nicholas Hawksmoor all had a say in the debate. Newton’s commentary describes the altar, the courts, the porticos, and the gates, based on a detailed comparison of the Hebrew text of the Old Testament with that of the Septuagint and the Vulgate, and includes quotations not only in Latin but also in Hebrew and Greek.

Another manuscript of note is a two-page piece written in Newton’s hand, headed simply “Lib. Chem,” and listing 119 chemical and alchemical books in his private library, apparently in a sort of shelf-list order. As one of the few sources to verify books undoubtedly in Newton’s library, it has proved especially useful in sorting out some of the provenance mysteries that resulted from the dispersal of Newton’s collection.

Correspondence by Newton’s contemporaries makes up the majority of the remaining Babson manuscripts. They concern mostly issues raised by Newton’s theories, and events bearing on his role as president of the Royal Society. One particularly interesting letter is from Leibniz to Nicolas Bernoulli, dated June 28, 1713. Leibniz’s priority dispute with Newton over the calculus was especially charged in the months following the release, in January 1713, of the Commercium Epistolicum, the report of the Royal Society’s investigation into the dispute, which concluded in favor of Newton. During this time, Bernoulli duplicitously encouraged Leibniz’s outrage and played the coy innocent to Newton’s followers. Leibniz presents several reasons in this four-page autograph letter justifying his claim to priority, and entreats Bernoulli’s outspoken help in the dispute.

The Grace K. Babson Collection is not restricted to books and manuscripts; it also contains important groups of prints, photographs, maps, medals, and coins. The most distinctive single item is a plaster death mask of Newton, one of only five known. The mask was the model for the sculptor Michael Rysbrack’s 1734 bust of Newton, as well as his work on the Westminster Abbey monument. The Grace K. Babson Collection’s version of the mask has a particularly distinguished history; it was almost certainly owned by Thomas Jefferson, who counted Newton among one his greatest heroes.

Sources of Collection

As Master of the Mint, Newton was held personally responsible for any debts at the Mint. At his death in 1727, Newton left no will, so his assets were frozen until the Mint was satisfied that the deceased had paid what he owed the Crown. The only family member wealthy enough to post bond and release the estate was John Conduitt, who was married to Newton’s beloved niece, Catherine Barton. The books in Newton’s private library were sold off for £300 to John Huggins, warden of the Fleet Prison, and given to his son, Charles.

Sometime after Charles’ death, the books were bought, along with Huggins’ house, by the Reverend Dr. James Musgrave. Following Musgrave’s death in 1778, the books passed to his family, in whose possession the collection remained more or less intact until 1920. At that time, descendants of the original Musgraves decided to sell the house where the library was kept, and about 1,000 volumes that were part of the original sale to Huggins were let go unwittingly for a mere £170. Some of these items resurfaced quickly in the market, but the majority disappeared.

Online Newton Project

The remaining 858 volumes were discovered in 1927 at the Wyckeham Musgrave home and offered for sale through the book dealer Sotheran for a startling £30,000. In 1936, the books remained unsold, and the price fell to £5,000. It was not until 1943 that the Pilgrim Trust paid £5,500 for a lot that included the 858 volumes, a 1655 edition of Euclid given to Newton by Isaac Barrow (traceable to the original thousand-volume sale), and a Greek Old Testament containing Newtonian annotations. This collection was given to Trinity College, Cambridge. All of those volumes contain original Huggins and Musgrave bookplates as well as a special Trinity bookplate designed by R.A. Maynard. As John Harrison has pointed out in The Library of Isaac Newton (Cambridge, 1978), of those books only 856 could have been from the Newton library, since a few have publication dates after Newton’s death.

Through the years, many of the lost thousand volumes have appeared on the antiquarian book market. Remarkably, the Grace K. Babson Collection includes 13 volumes known to be from Newton’s personal library, all bearing the Huggins and Musgrave bookplates. The Musgrave bookplate has, in most cases, been laid over the Huggins, and is marked with the shelf location for the volume in the Musgrave library at Barnsley Park, Gloucester. While the bookplates cannot be seen as a definitive arbiter of whether an item belonged to Newton’s library, or whether it is definitely from the original Musgrave sale, they do offer substantial clues to a book’s likely provenance.

The second major source of Newton materials was the famous 1936 Sotheby sale of what is known as the Portsmouth Collection. When Conduitt posted bond on the Newton estate, he claimed as a reward all of Newton’s unpublished papers, except those few deemed fit to publish, which were sent to press and the profit divided. The unpublished papers remained connected to the family estates until 1872, when the fifth Earl of Portsmouth decided to give many of the papers and other items to Cambridge University.

At this time, Newton’s copies of the Principia, with copious annotations and emendations in his hand, about a thousand pages of mathematical notes, the Waste Book (a folio notebook of early scientific and mathematical ideas), and other mathematical manuscripts were given to the university and placed in the University Library. The Portsmouth family retained the papers on chronology, theology, history, alchemy, and the materials for a biography compiled by Conduitt. In 1888, a catalogue of these papers was completed, but the wealth of the collection did not become apparent until the Portsmouth family sent it to auction in the 1930s.

The papers sold by the Portsmouth family form the core of most of the significant collections of Newton manuscripts throughout the world. The economist John Maynard Keynes purchased most of the alchemy manuscripts, as well as almost all of Conduitt’s notes, which he subsequently donated to the King’s College Library. Lord Wakefield purchased all 329 Mint lots, which he gave to the Mint in London. The majority of the theological manuscripts was purchased by Abraham Yahuda and later presented to the Jewish National and University Library in Jerusalem.

Principia Mathematica

Newton’s Philosophiae Naturalis Principia Mathematica is generally esteemed his masterpiece. This great work often is held to represent the culmination of the Scientific Revolution, in which science as we know it today was born. It is the founding treatise in the domain of rational mechanics, a term which was itself introduced into the discourse of science by Newton.

Among the concepts originated by Newton and appearing in the Principia, the most important is no doubt “mass,” introduced and named in Definition 1 of the Principia. In this work, there also are set forth the three Laws of Motion, generally known today as Newton’s laws. Here also is the first appearance in print of Newton’s invention of the calculus, the universal tool of the exact natural and social sciences.

What most attracted attention and admiration in the century after Newton’s book was published, however, was not his magisterial contributions to the new science of dynamics or his presentation of the differential calculus, but rather his “System of the World,” an explanation of the phenomena of our universe based on scientific principles—a gravitational cosmology. Here was a magnificent display of the power of the human mind strengthened and guided by science. Most people agreed with Sir Edmond Halley’s judgment in a poem he wrote as a kind of foreword to the Principia: “No mortal may approach nearer to the gods!”

The Editions

The Principia was published during Newton’s lifetime in three authorized editions: London, 1687; Cambridge, 1713; and London, 1726. During this time, there also were two unauthorized editions: Amsterdam, 1714; Amsterdam, 1723. The first edition occurs in two states, differentiated by the title page. The first (or original) bears the imprint “apud Sa. Smith.” The title page of the second state is a cancel, pasted on the stub of the original, or cancellandum; it bears the imprint “apud Sam. Smith . . . aliosque nonnullos Bibliopolas.” It was suggested by A.N.L. Munby, the first scholar to undertake a careful bibliographical study of these two states, that copies in the second state were intended for sale on the Continent. Munby estimated that this first edition was limited to between 250 and 300 copies of the first issue and about 50 of the second; more recently D.T. Whiteside has shown that the more likely total was 500. The second edition (1713) occurs only in a single state; the size of the edition was 750 copies. The third edition (1726) exists in three states. Most of the copies were printed on ordinary-sized paper; a certain number were printed on large paper; and a very few on extra-large paper (royal folio). The number of copies printed in these three states were as follows: 800, 25, and 10.

The Grace K. Babson Collection has a copy of each of these authorized editions: 1687 (both states); 1713; 1726 (all three states). Thus, in a single collection is every form of every edition of the Principia published before Newton’s death in 1727.

First Edition Special Copy

The Grace K. Babson Collection also contains a very special copy of the first edition, formerly in the possession of Miss Margaret Norman of Cremorne (New South Wales, Australia). This copy had been in the library of her great-grandfather, James Sprent, an Edinburgh, Scotland, astronomer who migrated to Hobart in 1837 and later became surveyor-general of Tasmania. This copy has a contemporaneous calf binding, containing a tool in gold in the corners, which differs from the tool (in blind) in the three copies known to have been presentations by Newton (currently in the Sidney Sussex and Trinity libraries, Cambridge—one of the two in Trinity is the copy presented by Newton to John Locke). The title page of the Grace K. Babson Collection’s copy bears an inscription, partly in Greek and partly in Latin, which may be translated as:

A remembrance of the cherished person of a most outstandingly learned and distinguished Author.

The handwriting is that of Sir Edmond Halley and the inscription almost identical to one in a copy of Newton’s Opticks (1704) that also belonged to Halley. This copy of the Principia is especially noteworthy because of the corrections to the text, mostly made by Halley. In the years following the publication of the Principia, Newton produced a number of corrections and improvements that were quite widely disseminated. These are described and listed in the Latin edition of the Principia with variant readings (edited by A. Koyré, I. Bernard Cohen, and Anne Whitman, 1971, vol. 2, suppl. 4; see “Introduction to the Principia,” 1070, p. 202). What is especially remarkable about the Babson copy is that at least six of the alterations were made by Newton in his own hand and appear in other annotated copies of the first edition. In the laudatory poem written by Halley, he suggested that the word ulva (sedge; ulvam in the accusative) be changed to alga (seaweed).

One of the puzzles of this copy is that it is printed on a thick paper, much coarser than the paper generally found in other copies of the first edition. This copy came to the Grace K. Babson Collection, following an auction at Sotheby’s, through Dawsons of Pall Mall. In Dawsons’ catalogue, Eric Osborn, then their chief cataloguer, described this as a proof copy largely because it is printed on coarse paper. This cannot be true. A comparison of the text of this copy and the manuscript used by the printer shows that it is of later date than the proof copy. Furthermore, there are no proof corrections preliminary to publication. The difference in paper remains a mystery.

Arithmetica Universalis

However, in 1707, William Whiston, Newton’s successor as Lucasian Professor at Cambridge, brought out an unauthorized edition of Newton’s Arithmetica Universalis, which was based on lectures that Newton had deposited in the University Library.

Newton so disliked this edition that he refused to have his name appear as author and even contemplated buying up the whole edition himself so that he could destroy it.

A second Latin edition, published in 1722, similarly bore no author’s name. Nor did Newton appear as author of the English version, published in 1720.

There is a copy of each of these editions in the Grace K. Babson Collection, together with other (and later) editions of works relating to Newton’s mathematics. The student of this subject has available the magnificent eight volumes of Newton’s Mathematical Papers, edited by D.T. Whiteside.

Analysis of Fluctuations

This book marks only the third appearance of Newton’s purely mathematical work in print. It is significant for both its content and for its role in the famous priority dispute between Newton and Leibniz over the invention of the calculus.

As a compilation, Analysis per quantitatum series, fluxiones, ac differentias contains four mathematical treatises and a sampling of correspondence, all related to Newton’s work on the calculus. Two of the treatises already had been published in Latin in the first edition of the Opticks (1704). These are the “Tractatus de quadrata curvarum” and the “Enumeratione linearum tertii ordinis.”

A third treatise is titled “De methodis differentialis.” It contains investigations of what are now known as the Newton-Bessel or Newton-Stirling formulas, which Newton had been working on as early as 1676, but which he had not published.

The jewel of this book, however, is the tract known as “De analysi per aequationes numero terminorum infinitas.” It was written by Newton in 1669 in response to his reading of Nicholas Mercator’s Logarithmotechnia. Mercator’s book contained developments tending in the direction of mathematical discoveries Newton already had made. Anxious to preserve credit for priority, Newton composed “De analysi,” which he gave to the great English mathematician Isaac Barrow. Barrow showed it to mathematician John Collins, who made a copy. This is important because Collins was at this time something of a clearinghouse for information about developments in English mathematics, and he showed “De analysi” to others.

“De analysi” thereby became the first systematic discussion of the calculus by Newton to circulate in public, and is thus one of the founding documents in the history of modern mathematics.

Containing the text of two of Newton’s earliest works, as well as his first two published treatises, the Analysis serves as a wonderful starting place for those studying the history of the calculus.

The Priority Dispute

A full history of the priority dispute between Newton and Leibniz concerning the invention of the calculus is not possible here, but the role of the Analysis in the affair demands a short account.

The story may be said to begin with the composition of the “De analysi” which, as mentioned above, was given to Isaac Barrow in 1669 and copied by John Collins.

When Leibniz independently began to work on the calculus in 1675, he was soon not only corresponding with Newton, through third parties, but also corresponding with Collins. Collins even showed Leibniz his copy of “De analysi.”

Scholars have determined that Leibniz did indeed arrive at his discoveries in the calculus independently. However, when he published his first work on the calculus in the Acta Eruditorum for 1684, Leibniz did not mention his correspondence with Newton or his exchanges with Collins. This gave the impression to many European mathematicians that Leibniz was the sole inventor of the calculus, because Newton had not actually published any of his mathematical work of the previous 20 years.

In 1693, however, John Wallis published a history of “fluxions” (which was Newton’s name for the calculus) in his Opera Mathematica. The publication of the Newton correspondence with Leibniz, which had taken place through intermediaries such as Henry Oldenburg, soon followed. Although Leibniz had always acknowledged Newton’s work in private correspondence, the grounds for a public battle were now set.

The first shot was fired by Nicolas Fatio de Diullier, who published comments in 1697 implying that Leibniz had plagiarized his calculus from Newton. In 1703, George Cheyne published Fluxionum methodis inversa, claiming that all work on the calculus in the previous 24 years was merely derivative of Newton’s original methods.

Newton now took a step in the dispute by publishing the two mathematical appendices to the Opticks in 1704. Newton was careful to mention that he had made his initial discoveries in 1664 and 1665. Newton also mentioned that he had referred to general methods of squaring curvilinear figures in correspondence with Leibniz as early as 1676, and that he had at one time lent out a manuscript describing these methods in more detail. “Having met with some things copied out of it,” Newton wrote—appearing to suggest that Leibniz was the copyist—he then decided to publish the material.

The next major event in the dispute was the publication of an article by John Keill, in the Philosophical Transactions of the Royal Society for 1708, who more or less directly accused Leibniz of having plagiarized the calculus from Newton, changing only the name (from fluxions) and method of notation. This edition of the Philosophical Transactions was not published until 1710, and Leibniz does not appear to have seen it until March of the following year. When he did read it, Leibniz wrote to the secretary of the Royal Society, demanding an apology.

When the letter arrived, Newton, who had been president of the Royal Society since 1705, collaborated in the composition of Keill’s response, which restated the charge of plagiary in even more inflammatory language. Outraged, Leibniz again wrote to the Royal Society to demand an apology.

Meanwhile, London mathematics teacher William Jones conceived the idea of publishing a volume of Newton’s mathematical works. Going through the papers of John Collins, who had since died, he found Collins’ copy of “De analysi.” Realizing that this copy represented independent proof of Newton’s priority in the invention of the calculus, Jones included it in the Analysis book of 1711, along with extracts from correspondence relating to the original exchanges between Newton and Leibniz that had taken place more than 30 years earlier. Accordingly, Jones’ volume now became an important part of the priority dispute.

How important it became can be seen from what happened after Leibniz’s second demand for an apology arrived for Newton who, as head of the Royal Society, set up a commission to judge the dispute. The commission naturally concluded in Newton’s favor, then published a report (almost certainly written by Newton) titled Commercium epistolicum d. Johannis Collins et aliorum de analysi promota (1712). That is to say, this report focused heavily on Collins’ copy of “De analysi” and his correspondence with Leibniz—all in support of Keill’s original charge of plagiarism.

The priority dispute was far from over, but the Analysis had now played a crucial role in its progress.


The second of Newton’s major writings on physical science was the Opticks, first published in 1704. The work represents a major contribution to science, different but in some ways rivaling that of the Principia.

The Opticks is largely a record of experiments and the deductions made from them, covering a wide range of topics in what was later to be known as physical optics. That is, this work is not a geometric discussion of catoptrics or dioptrics, the traditional subjects of reflection of light by mirrors of different shapes and the exploration of how light is bent as it passes from one medium, such as air, into another, such as water or glass. Rather, the Opticks is a study of the nature of light and color and the various phenomena of diffraction, which Newton called the “inflexion” of light.

In this book, Newton sets forth in full on his experiments, first reported in 1672, on dispersion, or the separation of light into a spectrum of its component colors. He shows how colors arise from selective absorption, reflection, or transmission of the various component parts of the incident light. His experiments on these subjects and on the problems of diffraction (which he never fully mastered) set the subject of optics on a new level.

The Optics and the Principia

The Opticks differs in many aspects from the Principia. First of all, it is written in English rather than Latin. Second, unlike the Principia, it is not presented in a strictly geometric form, with propositions proved by mathematics from either previous propositions (or lemmas) or first principles (or axioms). It does not prove its propositions by the use of ratios or equations, by the use of fluxions, or the tools of mathematics. Rather, the proofs generally proceed “by Experiments.” In many ways, therefore, this work is a vade mecum (“go with me” in Latin, or a handbook) of the experimenter’s art, displaying in many examples the way to make experiments and to draw proper conclusions from them.

The Queries

The Opticks concludes with a set of “Queries.” In the first edition, there were 16 such Queries; that number was increased in the Latin edition, published in 1706, and then in the revised English edition, published in 1717–1718. The first set of Queries was brief, but the later ones became short essays, filling many pages. These Queries, especially the later ones, deal with a wide range of physical phenomena, far transcending any narrow interpretation of the subject matter of “optics.” They concern the nature and transmission of heat; the possible cause of gravity; electrical phenomena; the nature of chemical action; the way in which God created matter in “the Beginning”; the proper way to do science; and even the ethical conduct of human beings.

These Queries are not really questions in the ordinary sense. They are almost all posed in the negative, as rhetorical questions. That is, Newton does not ask whether light is or may be a body. Rather, he declares: “Is not Light a Body?” Not only does this form indicate that Newton had an answer, but that it may go on for many pages. Clearly, as Stephen Hales (a firm Newtonian of the early 18th century) declared, this was Newton’s mode of explaining “by Query.”

Other scientists followed Newton’s lead. They saw that he had been setting forth a kind of exploratory natural philosophy in which the primary source of knowledge was experiment. This Newtonian tradition of experimental natural philosophy was different from the one based on mathematical deductions. In this sense, the Opticks established a kind of Newtonianism that in the 18th century rivaled in importance the mathematical natural philosophy of the Principia. Some of the primary adepts in this new philosophy were such giants as Benjamin Franklin, Antoine-Laurent Lavoisier, and James Black.

The Editions

The Grace K. Babson Collection contains four copies of the 1704 Opticks. Why, it may be wondered, is it necessary to have more than one copy of this rare and valuable classic? A close examination and collation of these copies shows that they differ in at least one very interesting respect. After the book had been printed, Newton found a fault that seemed to him too gross to be corrected by merely adding an “erratum” at the end of the volume, which already had been printed. Accordingly, as was the practice in those days, he ordered the printer to cut out a page and paste a substitute page (or cancel) onto the stub of the original. One of the Babson copies of the Opticks resembles most other copies in this regard, having the cancel instead of the original printed page, but a second copy has both the original page as well as the cancel. By means of these two copies we can trace the history of Newton’s involvement in the printing of this book.

Soon after the Opticks had been published in English, Newton commissioned a Latin version, which was made under his supervision by Samuel Clarke, the Clarke of the Leibniz-Clarke correspondence in the next paragraph. The Grace K. Babson Collection contains two copies of this work. These two copies reveal an interesting aspect of Newton’s change of mind immediately after the volume was printed.

In one of the letters in the Leibniz-Clarke correspondence, Leibniz declares boldly that in the “appendix” (the Queries) to Newton’s Opticks of 1706, Newton had said expressly, “Space is the Sensorium of God” (“l’Espace est le Sensorium de Dieu”). He thus contradicts Clarke, who had maintained that “Newton doth not say that Space is the Organ which God makes use of to perceive all things.” To confute Leibniz, Clarke quotes a passage in Latin from Query XX of the Latin edition, in which Newton refers specifically to God in his infinite space as “tanquam Sensorio su,” that is, “as if in his sensorium.”

How could there be such a disagreement between the readings of the text of the 1706 Latin edition of the Opticks? A comparison of several copies of this edition reveals the answer. The passage quoted by Clarke occurs on a page that is a cancel, pasted onto the stub of the original page. The original page, however, contains a rather different text, one in which the word “tanquam” is missing. The existence of two versions of Query XX was originally discovered by Alexandre Koyré in examining the copy of this edition in the library of the Institute for Advanced Study in Princeton. The difference between these two versions is apparent at once in comparing page 315 in the two copies in the Grace K. Babson Collection. It was later found that at least 16 copies exist in which the original page appears. Evidently the correction was either not done carefully or done after some copies of the book had been distributed. We may presume that Leibniz had gotten hold of a copy with the original page.

In 1717, Newton brought out a revised English version of the Opticks, now incorporating English versions of the queries that had been added in the Latin edition of 1706, plus some new ones. Then, in 1718, there was a second issue of this second English edition. Both issues are in the Grace K. Babson Collection. No one has as yet discovered exactly why there were two issues of this second English edition of the Opticks, nor has anyone as yet compared the two issues to find out what changes, if any, were introduced by Newton into the second issue.