I came across the following from Vancouver's account (A Voyage of Discovery to the North Pacific Ocean, and Round the World):

"The whole of the day being perfectly calm, with remarkable fine weather, induced me to embrace the opportunity of unbending all our sails which wanted alteration, and to bend an entire new suit; these I caused to be soaked over board for some hours, that the sea water might dissolve the size used in making the canvas, and by that means act as a preventive against the mildew in hot rainy weather."

I was wondering if anyone had run across this procedure before? Was it common practice to do this with new sails?