The history of Boulliau's manuscripts is far from clear.  It appears that a major portion of the present day Collection Boulliau came to the Bibliothèque du roi no latter than 1799 and probably before 1782.  This acquisition alone (noted by Leprince) records some eighty volumes which were subsequently re-bound, re-classified, and perhaps re-located in other libraries.  Identifying and locating these manuscripts has proven no mean task.  Moreover, there is no question that hundreds of items were later stolen, most notably by Guglielmo Libri (1802-1869), the most notorious archive thief of modern times.  I have located Boulliau manuscripts and letters now dispersed in over 60 libraries, archives, and private collections in a dozen countries. 

In September 1885 the noted Hebrew scholar Adolphe Franck completed the first inventory of the Collection Boulliau.  This handwritten register can be can be used by readers in the Salle des Manuscrits (Bureau, 58/6, Catalogues No. 376).  In 1978 I completed a comprehensive inventory of the Boulliau manuscripts and, after thorough re-checking, published The Collection Boulliau (BN, FF. 13019-13059):  An inventory, American Philosophical Society, 1983 (lxxiiii + 599 pp). 

This volume provides a folio-by-folio account of the Collection Boulliau; the volume can be consulted at any major research library.  A second revised and expanded edition is in preparation with the American Philosophical Society.