A photo copy of the original correspondence is posted on the site of the University of Nancy in France. See Poincare Correspondence and navigate to the letters for Kowalevski. The following letter was translated from the French by Yvonne Coates ©2006 Yvonne Coates

For biograpical links MacTutor History of Mathematics Archive - Biographies are used.

Notes enclosed [] were not in the text and are editorial comments added by the translator or by the creator of this site, Joan Spicci.

LETTER 2 FROM SOPHIE KOWALEVSKI TO HENRI POINCARE

Stockholm 1 May [1887] Engelheontogalan H. [somewhat illegible]

Monsieur, before [illegible, probably "examining"] M. Humbert's article, which you have kindly sent to M. Leffler, let me ask if you are aware of M. Weierstrass's treatment of the same question?  Unfortunately I don't think [that you are] as M. Weierstrass's demonstration is part of his course in Abelian integrals (which contains multiple installments that made up his course in Abelian integrals).  It is well known to all his students.  If you have never had the occasion to see this demonstration, permit me to write it out for you {here].

[3 pages of calculations follow in the original letter] 

If one considers the significance of the constants [in Weierstrass's demonstration], one can easily see that these conditions are the same as those found by M. Humbert.

I don't believe that Weierstrass ever published this research [illegible], but it is known in Germany and in Sweden; I therefore don't know, dear sir, if in analyzing the resulting identity, you would nevertheless judge it appropriate [that we] publish M. Humbert's article in the Acta [the journal Acta Mathematica].  I beg you to write me a few words [illegible, probably "on the subject"], and we will do as you wish (conform absolutely with your desires).  I would be very grateful if you would be willing (wish) to write soon, so your letter might reach me before May 15; I will be leaving Stockholm by then and count on being in Paris in early June.  I ask you, dear sir, to remember me to Mme. Poincare, and accept for yourself the expression of my highest regard.

[signed] Sophie Kowalevski

P.S.  I have just this moment received your beautiful articles on quadratic forms  [illegible] in the Notice [journal?] on your work and I express my profound gratitude for this parcel.