Dr. Hans Eduard Fierz-David 
Fundamental Processes of Dye Chemistry [PDF ebook] 

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. In most cases the original weights and prices have been retained (in francs per instead of trying to convert them into shillings per pound. It was felt that, as the figures referred usually to pre war conditions in Switzerland, and having regard to the present unsettled state of the exchanges and of production costs, no good purpose would be served by attempting to give the English equivalents which, in any case, would in all probability only be misleading.