Unfortunately, the study of the intestinal flora is extremely complicated because of the innumerable species of micro-organisms and the extreme difficulty of disentangling the many influences which cross each other. He therefore considered collective researches as indispensable, the life and science of one man being insufficient to solve so vast a problem. Up to a certain point he succeeded in realising this scientific collaboration within his own laboratory.
The Nobel Prize--Journey to Sweden and to Russia--A day with Léon Tolstoï.
In 1908 Metchnikoff received the Nobel Prize, together with Ehrlich, for his researches on immunity. According to the statutes of that prize, the laureate is invited to give a lecture in Stockholm. Metchnikoff chose for his theme the "present state of the question of immunity in infectious diseases," and, in the spring of 1909, we went to Sweden and thence to Russia. The whole journey was a series of fêtes and receptions in his honour. He was touched and grateful at this welcome, but with his usual humour, declared that it was the Nobel Prize which, like a magic wand, had revealed to the public the value of his researches.
We only stopped for a short time at Stockholm, where the kindest hospitality was shown to Metchnikoff. Sweden made an unforgettable impression upon us. Her deep, dark waters, wild rocks, and sombre pines make of it a land of legends. Elie was impressed not only by Nature in Scandinavia but also by Scandinavian Art, which reproduces it admirably. He was specially pleased with Lilienfiorse's pictures, representing animals against a background at the same time real and legendary.
We went to Russia by way of the Baltic. The nights at that time were "white," and rocky islands covered with pines emerged from the sea like ghosts, in the mysterious silvery midnight light; the impression was fairy-like.
A warm welcome awaited Metchnikoff in Russia. At Petersburg, as in Moscow, he was received with cordial and enthusiastic sympathy not only by scientific and medical societies, but by all the intellectual youth of those cities. This warm reception contributed to efface the bitterness sometimes aroused in him by distant recollections of the reasons which caused him to leave his native country.