He once made a remark to the effect that Eskimos had four unrelated root words for snow. Now, Boas' claim about language is an important tenet of modern linguistics, and one of his students, Edward Sapir, made important early contributions to the field. Whorf went on to publish what he called the Sapir-Whorf hypothesis, claiming that a person's thoughts are shaped and limited by his native language. He took Boas' claim that there were four unrelated root words, increased it to seven, and implied that there might be more. In time, the claim has been increased to truly impressive numbers.
Reality is much more boring.
As mentioned above, Boas found four unrelated roots. Furthermore, it is hardly surprising that Eskimos have four roots for snow - the ability to describe snow conditions is pretty important to someone living in the Artic. Hope this will do for the time being.