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i- 



ARMY SURGEON AT POTSDAM 37 



so sadly in melancholy strains ... an unsurpassable master- 

 piece/ 



The wedding could not take place until Helmholtz received 

 some permanent appointment, so the young man embarked 

 courageously upon his great scientific enterprise. By the 

 middle of February, 1847, ne na o! sent du Bois-Reymond the 

 sketch of his Introduction to the ' Conservation of Energy'. ' Not 

 because I think it is ready, for even in reading it over I see 

 that most likely none of it can stand, but because I do not 

 yet see how many times I shall have to rewrite it before it is 

 done, and I want to know if you think the style in which it 

 is written one that will go down with the physicists. I pulled 

 myself together at the last reading, and threw everything over- 

 board that savoured of philosophy, wherever it was not abso- 

 lutely essential, so this may have made some gaps in my logic. 

 Still you will be able to see the nature of the argument from 

 it. Don't put yourself out to read it ; do it at your leisure, and 

 then write to me : where you find obscurities or lacunae in the 

 details note them on the margin. I may come to Berlin myself 

 after a while to talk to you about it/ 



Du Bois received the Introduction with enthusiasm, and 

 declared that it must remain as it was, ' an historical document 

 of great scientific import for all time. 9 



It was during the first quarter of 1847, while he was on 

 field-hospital duty, that the young investigator found oppor- 

 tunity to formulate the ideas which he had cherished since 

 the beginning of his studies, and had tested by experiments 



the most disparate branches of physiology and physics with 

 a view to publishing the results. Neither he nor his friends 

 had any notion that other workers were engaged on the same 

 problems. When free of the hospital post, Helmholtz at once 

 resumed his experimental work, and reconstructed the apparatus 

 for his thermal experiments on muscle, giving much good 

 advice from his own experiences to du Bois about his experi- 

 ments, while he ' waited impatiently for the spring and the frogs'. 

 But once more he had to interrupt his experiments, since Halske 

 ept him waiting too long over the construction of a Neefs 

 nterruptor for his electrical apparatus, till finally the moment 

 for producing the ' Conservation of Energy ' before the world 

 rrived. 



