tetrodotoxin was present, hypothesized how this might have been done. The bokor (sorcerer) would have given Narcisse a powder containing the tetrodotoxin through abraded skin. Narcisse would then have fallen into a comatose state, closely resembling death, which resulted in his live burial. His body would then have been recovered and he would have been given doses of Datura stramonium to create a compliant zombie-like state, and set to work on a plantation. After two years, the plantation owner died and Narcisse would have simply walked away to freedom. Skepticism While in these popular accounts, and in Haiti, tetrodotoxin is thought to have been used in voodoo preparations, in so-called zombie poisons, subsequent careful analysis has repeatedly called these accounts and early analytical studies into question on technical grounds; moreover, they have failed to identify the toxin in any such preparation, such that discussion of the matter of tetrodotoxin use in this way has all but disappeared from the primary literature since the early 1990s. Kao and Yasumoto concluded in the first of their papers in 1986 (and remained unswerving on the matter in their later work) that "the widely circulated claim in the lay press to the effect that tetrodotoxin is ... causal agent" in a "zombification process" is, in their view, "without factual foundation." Kao, of the State University of New York, on interview on the matter in 1988, stated, "I actually feel this is an issue of fraud in science". A supporter of Wade, Bo Holmstedt of the Karolinska Institute, more restrained, stated that it was "not deliberated fraud," rather that it was "withholding negative data" and therefore "simply bad science." Davis responded formally to the charges, arguing the variability of the preparations (as cause for Kao's inability to find the toxin in any) and possible ineptitude in dissolving the toxin by the otherwise admittedly expert Kao, and speculating on the presence of "other ingredients" in the preparations to "enable transport across the blood–brain barrier" thus providing the needed "reduction of three orders of magnitude" of the amount needed to result in the claimed effects, and arguing that "only when the bokor … causes others to believe the victim is dead and then revived" do his efforts become apparent, and that only a single "success … would be sufficient to support the cultural belief in the … phenomenon." As of 1990, his critics were unpersuaded, and no