COWLES'S PATENT MOTH, MILDEW, AND WATERPROOFING TREATMENT AND THE U.S. ARMY, 1869–1876
Ann Cordy Deegan
The ingredients found in Cowles's process present challenges to conservators. Copper, zinc, mercury, and aluminum were used and, if retained, could yield false positives in laboratory tests for dye mordants. Although no lead was said to be in the solutions there may be other irritants present requiring care in handling. Gelatine or glycerine that provided water-repellency also may hold dirt on the fabric creating additional conservation work. The olive oil soap could also produce a tacky surface and lend an oleophilic nature to the fabric increasing oil stain retention.
Cowles's-treated garments can be identified by sleeve markings. These are most likely to be Civil War surplus items. Fabric treated with Cowles's solution and then made into garments will have no markings but would include the 1872 style of uniform since this process was applied from 1869 to 1876. Civil War surplus tents or those made during this era may also have been exposed.
Cowles's process proved to be effective as a moth and water-repellent product. Moths either were killed or made sluggish by the compounds. Water was repelled but on saturation allowed penetration (not waterproof). Mildewproofing tests were limited and provide less proof of actual success. Changes in hand and appearance were minimal with Cowles's treatment but if wool garments are wet cleaned they may show color change and possible stain spread. Conservationists planning to use wet cleaning should be cautious when dealing with items suspected or identified as Cowles's-treated. Any conservation treatment that may solubilize ingredients in the Cowles recipe should be considered carefully prior to treatment as irreplaceable historical evidence may be removed.