PREFACE. ix 



of the references, it being intended that the Bibliography 

 shall be published as an Appendix to the second volume. 

 This increases the desirability of the early appearance of the 

 latter. 



The Publishers have produced the work in a handsome 

 and substantial manner, and in this respect also the im- 

 pression produced is of the best. 



EMIL. CHR HANSEN. 



CARLSBERG LABORATORY, COPENHAGEN, 

 September 1896. 



