London, 25 October 1877 
41 Maitland Park Road, N. W. 

Dear Mrs Hess, 

Very many thanks from myself as well as from Engels for the 
two copies we have been sent of the ‘dynamic theory of matter’.* 

We are both of the opinion that the work of our late friend has 
very considerable scientific merit and does credit to our party. So, 
quite apart from our personal relations with an ally of many years’ 
standing, we would regard it as our duty to explain the 
significance of his work and to do all we could for its sales. 

Are the two parts announced in Hess’ foreword also available 
in manuscript? *” 

You will not take it amiss if I enclose herewith the price of the 
two copies, the point being, not so much your personal expense, as 
the cost of the undertaking. 

Yours very sincerely, 
Karl Marx 

I shall write to Petersburg and New York on the subject of the 
work.