field of Prestonpans. Mr Hay, who had been educated in the politicfal principles of his family, willingly accompanied his professor, and followed the fortunes of the army in its march into England.
On its retreat, his health being broken by exposure and fatigue, he was unable to proceed beyond Crieff, and therefore returned to Edinburgh in February 1746. As he had served not in a military but purely professional capacity, assisting indiscriminately the sick and wounded of both armies, he hoped he would be put to no trouble. He was soon undeceived, however, for he was first committed to Edinburgh Castle for three months, and thence removed to London along with other prisoners implicated in the same cause. In London his captivity was not a rigorous one, but twelve months elapsed before his liberation under the Habeas Corpus Act in June 1747.
For himself he had no longer any cause of apprehension, but fearing lest he might be cited in evidence against some of the unfortunate adherents of the Stuarts, he retired to the seat of Sir Walter Montgomery, a relative in Ayrshire. As soon as all danger of this seemed past, he returned to Edinburgh and resumed his medical studies. Other important matters, however, now occupied his thoughts. Naturally he was of a serious cast of mind, and this had been strengthened by early training. But that he had no Catholic tendencies is sufficiently evident from the fact, that in the fervour of youth he had bound himself by a double vow to read a portion of the Bible daily, and to do his utmost to extirpate Popery from his native country. In London, however, he had chanced to hear the doctrines of the Catholic Church explained by an English gentleman, in a manner which excited his surprise; and in his retreat in Ayrshire he had fallen upon a well-known little work, A Papist
