Many people are unaware that researchers have found evidence of substances derived from tobacco and coca in tests conducted on ancient Egyptian mummies. Children being taught conventional views of mankind's ancient history in school are rarely if ever given all the evidence and encouraged (or even permitted) to form their own conclusion based on their analysis of the preponderance of evidence. The presence of substances such as tobacco and coca is ignored, suppressed, or dismissed as "pseudoarchaeology" because such substances present a very difficult problem for the reigning academic theories.
It is generally agreed that tobacco and coca are New World plants, unknown to Old World civilizations prior to 1492. Detection of tobacco and coca in ancient Egyptian mummies implies extremely ancient contact across the oceans, and not mere chance contact either. It is one thing to admit the possibility that a random Mediterranean ship was somehow blown off course and made it to the New World, and then somehow returned, but the detection of tobacco derivatives and coca derivatives in the hair follicles of ancient mummies indicates familiarity and ongoing use -- evidence for deliberate, ongoing, long-term trans-ocean contact and a "logistics chain" for obtaining such plants.
Here is an article from the website of Colorado State University discussing the most well-known tests which found evidence of coca- and tobacco-derived substances in Egyptian mummies (namely cocaine and nicotine). It argues that, although the initial reaction to the publication of the results of this study in 1992 was skepticism and disbelief from the academic community, that reaction was based primarily upon firmly-held assumptions about the ancient history of mankind and not upon the evidence itself.
This article describes the earlier discovery in 1976 of plant fragments within the wrappings of the mummy of the well-known and powerful Pharaoh Ramses II (or Ramesses II). Close examination of the fragments revealed that they were tobacco. The theory that these tobacco fragments were somehow dropped there from the cigar or pipe of a nineteenth-century archaeologist was later weakened by the discovery of further tobacco inside the abdomen of the mummy itself. Nevertheless, many skeptics continue to maintain that any evidence of tobacco products in the Ramses II mummy must have been introduced later.
The Ramses II mummy also contains evidence of cannabis, which was known in the Old World (although not generally associated with the region and culture of ancient Egypt). Strangely, nobody seems to argue that nineteenth-century archaeologists accidentally dropped cannabis into the mummy.
The evidence from the Egyptian mummies is sensational, and perhaps more easily dismissed as fringe science because of our own (very strong) cultural perception about drugs and tobacco. However, it is by no means the only evidence of plant species which point to ongoing and regular ancient trans-Atlantic contact. This extensive study by two university professors lists plant after plant, many of them having nothing to do with altered states of consciousness, presenting extremely strong evidence for ancient contact between the "Old World" and the "New World." Species include jimson weed (native to North America, found in Europe and Asia), marigolds (also native to the New World, found in China and India), sarsparilla (native to the Old World, found in Central America), and certain breeds of cotton from the Old World found in South America, all with evidence indicating pre-Columbian transport of these plants.
Defenders of the prevailing timeline of history can labor mightily to dismiss the presence of coca and tobacco substances in ancient Egyptian mummies, but in the end this evidence is simply one more data point in a huge web of other evidence. In fact, even if it turned out that all the scientific studies which found coca and tobacco among these mummies were mistaken or even fraudulent, it would not really matter. The other evidence is overwhelming that ancient trans-oceanic contact did take place. For previous discussions of some of this evidence, see also this post, this post, and this post (among others), and the evidence discussed in the Mathisen Corollary book itself.