Albert Einstein's private diaries reveal the iconic scientist's racist attitudes on a trip to Asia in the 1920s.

In the autumn of 1922, Albert Einstein, along with his then-wife, Elsa, embarked on a five-and-a-half-month voyage to the Far East and Middle East, regions that the renowned physicist had never visited before.

Einstein's lengthy itinerary consisted of stops in Hong Kong and Singapore, two brief stays in China, a six-week whirlwind lecture tour of Japan and a twelve-day tour of Palestine.

Einstein arriving in Kobe, Japan as part of his five-and-a-half month tour of the Middle and Far East. His opinion of the Japanese was more favourable than that of the Chinese

The diaries have been published first time as a standalone volume in English by Princeton University Press, including facsimiles of the diary pages.

Einstein, who once described racism as 'a disease of white people', describes the Chinese as 'industrious, filthy, obtuse people', The Guardian reported.

'Chinese don't sit on benches while eating but squat like Europeans do when they relieve themselves out in the leafy woods.

'All this occurs quietly and demurely. Even the children are spiritless and look obtuse.'

He also writes of the 'abundance of offspring' and the 'fecundity' of the Chinese.

'It would be a pity if these Chinese supplant all other races. For the likes of us the mere thought is unspeakably dreary.'

He says of the Chinese 'even those reduced to working like horses never give the impression of conscious suffering. A peculiar herd-like nation…often more like automatons than people.'

An excerpt from the diaries written by Einstein. They have been translated into English as a stand alone edition for the first time

In Colombo, in what was then called Ceylon and now Sri Lanka, Einstein says the locals 'live in great filth and considerable stench at ground level' adding that they 'do little, and need little. The simple economic cycle of life'.

He does appear to have more favourable impression of the Japanese who he says are 'unostentatious, decent, altogether very appealing'.

'Pure souls as nowhere else among people. One has to love and admire this country.'

The Travel Diaries of Albert Einstein have been edited by Ze'ev Rosenkranz, senior editor and assistant director of the Einstein Papers Project at the California Institute of Technology.

'I think a lot of comments strike us as pretty unpleasant - what he says about the Chinese in particular,' he told The Guardian.

'They're kind of in contrast to the public image of the great humanitarian icon. I think it's quite a shock to read those and contrast them with his more public statements. They're more off guard, he didn't intend them for publication.'

The diaries have only previously been published in German as part of the 15-volume Collected Papers of Albert Einstein.