At this point it may be worth a reminder of the writings of George Washington Sears, aka "Nessmuk", from his book: "Woodcraft and Camping", first published in 1884 and is still available for sale in paperback, or for free online. From page 13 (bold emphasis added):
As regards poisonous insects, it may be said that, to the man with clean, bleached, tender skin, they are, at the start, an unendurable torment. No one can enjoy life with a smarting, burning, swollen face, while the attacks on every exposed inch of skin are persistent and constant. I have seen a young man after two days’ exposure to these pests come out of the woods with one eye entirely closed and the brow hanging over it like a clam shell, while face and hands were almost hideous from inflammation and puffiness. The St. Regis and St. Francis Indians, although born and reared in the woods, by no means make light of the black fly.
It took the man who could shoot Phantom Falls to find out, “Its bite is not severe, nor is it ordinarily poisonous. There may be an occasional exception to this rule; but beside the bite of the mosquito, it is comparatively mild and harmless.” And again: "Gnats...in my way of thinking, are much worse than the black fly or mosquito.” So says Murray. Our observations differ. A thousand mosquitoes and as many gnats can bite me without leaving a mark, or having any effect save the pain of the bite while they are at work. But each bite of the black fly makes a separate and distinct boil, that will not heal and be well in two months.
While fishing for brook trout in July last, I ran into a swarm of them on Moose River, and got badly bitten. I had carelessly left my medicine behind. On the first of October the bites had not ceased to be painful, and it was three months before they disappeared entirely. Frank Forester says, in his Fish and Fishing, page 371, that he has never fished for the redfleshed trout of Hamilton county, “being deterred therefrom by dread of that curse of the summer angler, the black fly, which is to me especially venomous.”
“Adirondack Murray” gives extended directions for beating these little pests by the use of buckskin gloves with chamois gauntlets, Swiss mull, fine muslin, etc. Then he advises a mixture of sweet oil and tar, which is to be applied to face and hands; and he adds that it is easily washed off, leaving the skin soft and smooth as an infant’s; all of which is true. But, more than forty years’ experience in the woods has taught me that the following recipe is infallible anywhere that sancudos, moquims, or our own poisonous insects do most abound.
It was published in Forest and Stream in the summer of 1880, and again in ’83. It has been pretty widely quoted and adopted, and I have never known it to fail: Three ounces pine tar, two ounces castor oil, one ounce pennyroyal oil. Simmer all together over a slow fire, and bottle for use. You will hardly need more than a two ounce vial full in a season. One ounce has lasted me six weeks in the woods. Rub it in thoroughly and liberally at first, and after you have established a good glaze, a little replenishing from day to day will be sufficient.
And don’t fool with soap and towels where insects are plenty. A good safe coat of this varnish grows better the longer it is kept on—and it is cleanly and wholesome. If you get your face and hands crocky or smutty about the campfire, wet the corner of your handkerchief and rub it off, not forgetting to apply the varnish at once, wherever you have cleaned it off. Last summer I carried a cake of soap and a towel in my knapsack through the North Woods for a seven weeks’ tour, and never used either a single time.
When I had established a good glaze on the skin, it was too valuable to be sacrificed for any weak whim connected with soap and water. When I struck a woodland hotel, I found soap and towels plenty enough. I found the mixture gave one’s face the ruddy tanned look supposed to be indicative of health and hard muscle. A thorough ablution in the public wash basin reduced the color, but left the skin very soft and smooth; in fact, as a lotion for the skin it is excellent. It is a soothing and healing application for poisonous bites already received.
