The Babson Collection contains approximately sixty manuscript items. They represent nearly the full range of Newton's activities; including correspondence, calculations, elaborate alchemical and theological musings, and bookkeeping receipts.

About forty are in Newton's hand, often signed, including a beautifully illustrated alchemical text picturing the Philosopher's Stone. Another, the twenty six-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 eighty-four-page autograph manuscript entitled "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 eighteenth 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 some one-hundred and nineteen chemical and alchemical books in his private library, apparently in a sort of shelf-list order (Ms. 418). 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' 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. In this four-page autograph letter, Leibniz presents several reasons justifying his claim to priority in the invention of the calculus.