In 1703 and 1704 he was surgeon to two of Her Majesty’s ships “where a delirium, stupor and phrenitis” were found as symptoms of the fevers. In the summer of 1704, cruising in the latitudes of Portugal and Spain, the men brought on board from Lisbon unripe lemons with which they made great quantities of punch. This was the evident cause of a cholera morbus and dysentery: “after this we had a pretty many taken with the _synochus putris_, and some with the _causus_” [malignant fever]. Most of these fevers went off by a crisis in sweating, “which was so large I had good reason to believe it judicatory.” In several the fevers left on the 9th, 10th or 11th day, and in almost all by the 14th. “About the latter end of July, and in August, there were many taken with a delirium and stupor or coma, and some with the phrenitis in their fever.” Among the symptoms was one which we find described for fevers on board ship on the West Coast of Africa at the same time--“soreness all over as if from blows with a cane,” a symptom afterwards associated with dengue. “Sometimes the bones (as they term it) don’t pain them much.” In some cases there were petechial spots as well as a stupor. In the month of August “the fevers with a stupor and phrenitis” came on apace. The treatment was to take ten ounces of blood every day from the second to the eighth day of the fever, to give tartar emetic in five-grain doses at the outset, and to administer cathartic glysters in the second half of the fever. “Seeing the lustiest men now ran no more hazard of their lives than any other who were usually taken with this fever, nor indeed so much, in the beginning of September I resolved, after all the phlebotomy was done in these fevers, to try the cathartic sooner.” Many of these who had accustomed themselves to the liberal use of spirituous liquors miscarried in the phrenitis. White left the navy in 1704 and settled in practice at Lisbon, where he saw much fever. He had seen epidemics break out in British ships of war at anchor in the Tagus, crowded with men and prisoners. One case he mentions in a Lisbon woman, with continual synochus, stupor, and petechiae on the fifth day: “This was contagious, for she got it by going often to assist a gunner of a man-of-war, who came to her house with this distemper upon him: for many at the same time on board that ship were sick of that disease.” Among the causes of fever on board ship he mentions the effluvia of the bilge-water.