Museum Jany. 30. 1806.
Since the receipt of your favor of the 23d. having the determined size of the Polygraphs, the work goes on with spirit, and I flatter myself that you will be pleased with the execution, as well as with the Mahogany, it is pretily cloulded but without knots. Some people admire knots in their Mahogany furniture, and I have observed that it is very liable to crack, this is a sufficient reason for my rejecting it. Silver makes better Pen-arms than I expected, being well hammered they are elastic and not liable to bend, as before tryal I had my apprehensions.
With respect to preserving fur Cloaks coverlids &c, it is an important object, therefore I will particularise. In the first place the means I make use of to preserve the coats of my large Animals, although perhaps the most effectual means yet thought of, however not advisable to be used in any wearing apparel; the poison which preserves them in every situation, might be inhaled in small particles to the injury of our health. As you wish to keep some Indian dresses at your Mansion, and parts of them may be liable to the depredations of Dermests, the mode of preserving may be applied to the perishable parts as I do with my large Animals. When I have a number of large Animals to do, I make use of large vessels and put 2 or 3 Wt. of arsenic into hot water, and completly wet all the furs & skins—but for a few or smaller subjects, I have a large Earthen Crock into which I put a half wt., more or less, of Arsenic, and then a Tea-kittle of boiling water may be sufficient to wet a considerable number of small subjects—this may be done with a Mop, if the articles are too large to be diped into the water. Hot water not only obtains a greater proportion of the Arsenic, but also will penetrate the natural grease of Skins, fur or feathers. This process is best done out of doors to avoid the fumes of the arsenic, wetting the hands much, will cause considerable inflamation to the ends of the fingers, Cuts or sores will be made worse if wet with the arsenical water. The advantage of washing subjects with this water are that they will keep free from the depredation of Insects a great length of time, 15 Years I have tested articles that have been put with others that have been eatin entirely to pieces, and the dermest would not touch the washed Skins. After animal Substances are well dyed, if they are put into boxes, air tight, they will be preserved, but great care must be taken to secure them before the fly has laid its eggs in them, or they may be baked in an Oven which shall be so hot as to dry up the Eggs, which may be done without injuring either feathers or fur—such a heat as an Oven is left in after bread is taken out. I have heard of many means that has been used to prevent damage made by Moths, some woolen Merchants, put Tallow Candles amongst the bales of Cloath; Mrs. Rittenhouse used to put a piece of Candle in her husbands pockets of his coats &c laid by during the summer season and she told me that it prevented them from being eaten by Moths. I have tryed musk, Capho &c but I have found no dependance on any means, except the arsenical water, or puting the articles in tight boxes. The experience you may have had by puting your furs into linnen shews that they may be keept from the Moth, if put up before the fly begins to moove in the Spring. but if they are first made wet with clean soap suds, then dryed before packed up, the alcaline however trifling it may be, will be disagreable to the fly. The question now is, for the easiest mode to secure the fur, and have the use of it occasionally? Perhaps the manner of my keeping the duplicate subjects of my Museum, is the most secure, and does not give much trouble to come at them. I have Boxes lined with Tin, these have the cover made to fit close, and besides have 2 layers of Shammoy or allum leather or the edge of the Box & cover, and having Staples in the Box and when the Cover is put on, Wedges are drove through the Staples which force the cover extreemely tight on the box, thus making them air tight. A case of this kind would keep all your furs secure from the depredations of all sorts of Insects, and fastenings of the Cover may be Screws or levers of sufficient power. If you approve of this method of secureg your furs, the manner of fastening, you will soon contrive to your Mind. The moth begins to fly here about the middle of May and ceases about the middle of Sepr. probably they may moove sooner and continue longer in the southern States. Furs ought to be baked, or very well beat if they are keept in the open air within those periods. I dont know whether I have given you any thing new in the above sketch, but the hope of serving you induced me to be thus lenthy. except the good will of your friend
DLC: Papers of Thomas Jefferson.