Introduction 
xxx 
Institut, i <5 j Sorbonne, 18). 1 It is clear then that, so far as 
concerns the autographs of Descartes alone, 2 Mr. Buxton’s 
Collection is equal in number to two-thirds of the total of 
those existing elsewhere, and is in itself more than three 
times as large as any other single assemblage ; and we may 
add that it is unique not only in size but also in com 
pleteness, since in the Huygens series we have the other and 
complementary side of what forms one correspondence. 
§ 2. Of the 12 6 letters and documents contained in the 
new Collection the large majority are here published for 
the first time. The exceptions are : 
Fourteen of the letters of Descartes to Huygens (V, XXIV, 
XXVII, XXXII, XXXIV, XXXV, XXXVIII, XL1II, 
LVI, LVIII, JLXXVII, LXXX, LXXXI, LXXXHI), all 
published from copies by the first editor of Descartes’ 
correspondence, Clerselier ; 
Seventeen of the letters of Huygens to Descartes (II, III, IX, 
XV, XXX, XXXI, XXXIII, XXXVII, XLI, XLII, 
XLIX, LVII, LXIV, LXXII, LXXXIV, XCV, C), all 
from copies found among the Huygens manuscripts at 
Amsterdam, first published by M. Adam in a communica 
tion to the Revue bourguignonne de PEnseignement supérieur 
for 18 9 y 3 ; 
Three of the documents, two of which (CXXIII and 
CXXIV) have been published before in their entirety, one 
(CXXV) in an abbreviated form. 
Taking no account of the portrait (CXXVI), we have 
then in the Collection fifty-two letters of Descartes, twenty- 
nine of Huygens, three of Van Surck, one of Mersenne, and 
six documents, in all ninety-one letters and documents, 
hitherto unknown and entirely new. 
1 For the figures see M. Adam’s Introduction to his monumental edition 
of the works of Descartes, vol. I, pp. Ixviii-lxx. 
3 Huygens’ autographs are neither so rare nor so important. 
3 See the Bibliography below, p. Ixv.