D O C U M E N T 4 2 6 J A N U A R Y 1 9 2 5 6 4 7 426. From Satyendra Nath Bose 17, Rue de Sommerard Paris Ve, 27th January ’25 Revered Master: I received your kind note of 3rd Nov. in which you mentioned your objections against the elementary law of Probability.[1] I have been thinking about your objec- tions all along, and so did not answer immediately. It seems to me that there is a way out of the difficulty, and I have written down my ideas in the form of a paper which I ¢enclose² send under a separate cover.[2] It seems that the one hypothesis of negative Einstrahlung stands, which as you have yourself expressed, reflects the classical behaviour of a resonator in a fluctuating field. But the additional hypoth- esis of a spontaneous change, independent of the state of the field seems to me not necessary. I have tried to look at the radiation field from a new standpoint, and have sought to separate the propagation of Quantum of energy from the propagation of electro-magnetic influence. I seem to feel vaguely that some such separation is nec- essary if Quantum theory is to be brought in line with the Generalised Relativity theory. The ideas about the radiation field, which I have ventured to put forward seem to be very much like to what Bohr has recently expressed in May Phil mag. 1924.[3] But it is only a guess, as I cannot say honestly to have exactly understood all what he means to say, about his virtual fields and virtual oscillators. I am rather anxious to know your opinion about it. I have shown it to Prof Langevin[4] here and he seems to think it interesting, and worth publishing. I cannot exactly express how grateful I feel for your encouragement and the in- terest you have taken in my papers. Your first p[ost]. card[5] came at a critical mo- ment, and it has more than any other made this sojourn to Europe possible for me. I am thinking of going to Berlin at the end of this winter, where I hope to have your inestimable help and guidance. Yours sincerely, Sn Bose. ALS (Wali 2009, pp. 324–325). [6 131]. [1]See Doc. 356. [2]For an analysis of the likely contents of this missing manuscript, see Ghose 1994, pp. 62–68. [3]Bohr, Kramers, and Slater 1924a. [4]Paul Langevin. [5]Doc. 279.