Table of Contents 
THE CORRESPONDENCE OF DESCARTES AND 
CONSTANTIJN HUYGENS. 
(Letters already published elsewhere from copies are distinguished by an 
asterisk. For details see the prolegomena at the head of each. 
For the supplementary numbers see Introduction A, § 3, p. xxxi.) 
Serial number 
I. 
From Huygens to 
II.* 
Huygens 
II a. 
Descartes 
Ill* 
Huygens 
IV. 
Descartes 
V.* 
Descartes 
VI. 
Descartes 
VII. 
Huygens 
Vila. 
Descartes 
VIII. 
Descartes 
IX* 
Huygens 
X. 
Huygens 
XL 
Descartes 
XII. 
Huygens 
XIII. 
Descartes 
XIV. 
Descartes 
XV* 
Huygens 
XVI. 
Huygens 
XVII. 
Descartes 
XVIII. 
Huygens 
XIX. 
Descartes 
XX. 
Descartes 
XXL 
Huygens 
XXII. 
Descartes 
XXIII. 
Descartes 
XXIV* 
Descartes 
XXV. 
Huygens 
XXVI. 
Descartes 
XXVIL* 
Descartes 
XXVIII. 
Huygens 
XXIX. 
Descartes 
XXX* 
Huygens 
XXX a. 
Descartes 
Date 
PAGE 
Descartes 
6 May 1637 
I 
Descartes 
18 Oct. 16^3 5: 
1 
Huygens 
1 Nov. 1635 
5 
Descartes 
7 Dec. 1635: 
7 
Huygens 
8 Dec. 1635" 
9 
Huygens 
11 Dec. 1635- 
11 
Huygens 
18 Mar. 1636 
*5 
Descartes 
31 Mar. 1636 
l 7 
Huygens 
[31 Mar. 163 <S] 
*9 
Huygens 
11 June 1636 
Descartes 
17 June 1636 
XI 
Descartes 
11 July 1636 
*3 
Huygens 
13 July 1636 
X4. 
Descartes 
13 Oct. 1636 
x(S 
Huygens 
30 Oct. 1636 
z 7 
Huygens 
1 Jan. 1637 
*9 
Descartes 
y Jan. 1637 
30 
Descartes 
xy Feb. 1637 
3* 
Huygens 
x7 Feb. 1637 
33 
Descartes 
1 Mar. 1637 
37 
Huygens 
[3 Mar. 1637] 
36 
Huygens 
xx Mar. 1637 
38 
Descartes 
X4- Mar. 1637 
39 
Huygens 
xp Mar. 1637 
41 
Huygens 
xo Apr. 1637 
44 
Huygens 
xo May 1637 
45 
Descartes 
x June 1637 
4-8 
Huygens 
[June 1 (S3 7] 
49 
Huygens 
ix June 1637 
7 1 
Descartes 
x7June 1 (S3 7 
73 
Huygens 
5 July 1637 
54 
Descartes 
18 Sept, 1637 
77 
Huygens 
7 Oct. 1637 
58 
xxn