The world of Walther Nernst
The book is subtitled 'The rise and fall of German science', and I would say that it is more a general look at science in Berlin than about Nernst in particular. Indeed Mendelssohn, a German Jew who left the country soon after the Nazi party came into power, seems to be wistful about what might have been if the country hadn't followed such disastrous paths. Firstly there was the Bismarkian rise of a Germany in which science played a central part, and a scientist such as Nernst could become an establishment figure. Then came the revolutionary science in Germany of the 1920's, in which Mendelssohn played a significant part. Thus Mendelssohn expresses his horror at the rise of the Nazi party. However, he doesn't give any deep analysis of the situation and tends to present the decision to leave the country as being a simple one to make, rather than the difficult choice that it was for many of his contemporaries.