Ohituary Notices. 
Vll 
Dittmar was a good all-round chemist. His discovery of glutaric 
acid showed that he was quite at home in organic chemistry ; hut 
it was as an analyst that he was great. His investigation into the 
compositions of the specimens of sea- water collected by the “ Chal- 
lenger” Expedition is full of instruction in the way such work 
should be done. And in all his analytical work, and in all his 
teaching, his aim was not so much to perfect or to teach methods of 
analysis, as to settle and teach principles from which methods can 
be deduced as they are wanted. He was quick to detect sources of 
error, and estimate their effect on results. As the great instrument 
of the analyst, the balance early attracted his attention, and some 
of the most important improvements in the construction of the 
balance are due to him. Besides the work already mentioned on 
the quantitative composition of water, and on the composition of 
sea-water, the determination of the atomic weight of platinum, and 
the examination of the hydrates, carbonates, and peroxides of the 
alkali metals may be specially noted. Very interesting also are his 
investigations into the relation of the composition of acids of 
constant boiling-point to the pressure under which they are 
distilled. 
Dittmar was an admirable teacher. He communicated to his 
students something of his own love of accuracy, and, instead of 
merely telling them what to do, and seeing that they did it, he 
also taught them to think for themselves. The transparent sim- 
plicity of his character, and the honest frankness of his manner, 
made his friendships close and constant rather than numerous. 
