Letter from K Fuchs, regarding two papers 'Matrix theory of correlations in a lattice. Part I' and 'Matrix theory of correlations in a lattice. Part II' by R Eisenschitz Sectional Committee: Mathematics Encloses the manuscript and a letter from Max Born. The minor modifications have not met the criticisms of the paper, and have not improved it. Only a complete revision of the paper will make it readable. The physical significance of the treatment should not be overruled by abstract mathematics. Comments on the term 'fictitious lattice' and use of the square net for illustrative purposes. The paper is important new method for the evaluation of the partition function, and it 'would be a pity if no one except [the author] should ever know this'. [Published in the 'Proceedings of the Royal Society of London'] No received date. 9 October 1942