1755 and all that: a historical primer of transmissible spongiform encephalopathy

In the political and economic turmoil of 18th century Europe, England gradually established itself as the dominant trading power. By far its most important commercial product was woollens, involving in one way or another nearly a quarter of the British population, which at 10 million people approximated the number of British sheep. Sir Robert Walpole, the embodiment of pragmatic mercantile economics, was prime minister of an increasingly powerful and commercially inclined Whig government, and, with the agricultural revolution in full swing, the invention of the flying shuttle and spinning jenny and the imminent introduction of steam power would soon convert weaving from a handicraft to a mechanical process. Wool, already in short supply, was at a premium. In this setting, it is not surprising that in 1755 a discussion took place in the British parliament about the economic effects of a fatal and spreading disease in sheep, and the need for government to do something about it.1 Thus began the recorded history of scrapie.