ARSENIC AND OLD COLLECTIONS

By Carl W. Albrecht, Curator of Natural History, Ohio Historical Society

Local History Notebook, March / April 1993

By the middle of the eighteenth century, collectors of natural history specimens were experiencing and writing about serious problems with the preservation of their specimens. Writing in the 1740s, one author "observed that collectors of natural history specimens'...had the Mortification to see them every Day destroyed by ravenous insects ..... Insect depredations were indeed the greatest problem facing collectors prior to the second half of the eighteenth century."(1)

The primary techniques of preservation that were available to collectors of the time largely were limited to three classes-"pickling of specimens in alcohol, embalming or fixation of anatomical preparations, and mounting by crude taxidermy techniques followed by drying--especially heat."(2)

All three of these methods had some successes, but they involved problems as well. Preservation in alcohol required very tightly sealed containers and severely restricted the display potential of specimens. The method of injecting anatomical preparations with materials such as quicksilver or wax produced good display specimens, but it was not practical for very small or very large specimens. Drying specimens sometimes involved preservation with salt, or stuffing with "herbs, alum, spices, and tobacco," followed with repeated fumigation and baking. All of these techniques, however, could cause as much damage to specimens as the insects might have done.

In the latter part of the seventeenth century, naturalists developed a new class of techniques for preserving bird and mammal skins. They substituted a new group of very strong and effective poisons for those that had been used on dried skins before. Mercuric chloride, also known as corrosive sublimate, was one of the early of these toxic poisons. Workers developed a preservative powder that they rubbed into the inner surface of bird skins. Also, some preparators expanded the preservation of birds to include treatment of feathers with mercuric chloride dissolved in water. This wet treatment, in turn, was extended to other specimens, such as insects, nuts, seeds, and the inner surfaces of bird and mammal skins.

Mixtures of arsenic and soap, often with other ingredients, were developed early on. These were to persist well into the twentieth century as widely used poisons in the preparation of natural history materials. Naturalists developed many variations, including rubbing arsenic with vaseline or powdered chalk when wet treatments were not appropriate. Also, they sprayed or dipped specimens in various poisonous solutions. And, the types of materials that were treated expanded to include botanicals, bones, fur rugs, and anthropological objects. Poisons, especially arsenic, as you will see, could cause severe problems for people who handled them.

Often unknown to managers and curators, museums today frequently have these objects and specimens in their collections. After having been collected and prepared many years ago, and stuffed and mounted using the accepted techniques of the day, these potentially dangerous objects have found their way into today's institutions. Museums may receive these "curatorial time-bombs" from private collections or other museums. Regardless of the source, however, wary professional and volunteer curators must handle all specimens with caution.

History Museums with Natural History Collections

Recently, a ready-made case study of nineteenth-century preparation of natural history specimens came my way. I was asked to examine a large collection of natural history specimens that had been in storage for over three-quarters of a century. This collection had been assembled during the years following the Civil War. It included a great many mounted birds and mammals as well as the expected insects, pressed plants, rocks, minerals, and sundry other specimens. Many of the specimens were common to the area, but I noted at least two fine examples of species that today are endangered and protected, and possibly one specimen of an extinct species. Most of the specimens were still in the glass and wooden cases in which they had been displayed for several decades until the display area displayed was closed to public access early in this century. The construction of the glass cases was hardly up to present-day standards for such enclosures, but, for the most part, the specimens were clean.

One thing that stuck me almost immediately, however, was the curious lack of any apparent damage to the specimens. There were, of course, empty pins surrounded by dust in some of the insect trays, and many of the pressed plants were in poor condition. But where were the dead moths? Why were there no shed larval skins from carpet beetles? How was it that all of the mammals still had their hair? And why were the floors of the not-so-tight cases clean, except for a little dust?

One thing in favor of preserving the specimens was that the area in which they were stored had no climate control, not even simple heating in the winter. Everything, therefore, had been exposed to high summer and sub-zero winter temperatures for the better part of one hundred years. These factors would have helped in pest control, but it did not seem to me that they explained away the conditions that I saw.

The possibility of poisons in the specimens themselves, occurred to me, but I decided to look for evidence of the collector having used these in his preparations before suggesting that the custodians of the collection have the collection tested chemically. Since I wanted to learn more about the naturalist himself, I began to examine the standard sources. I found him where I expected in both the censuses and directories of the period, and there was a modest note in one of the county histories. Looking further, I found his obituary. It said that he died "from a complication of diseases after [he] had been in poor health for several years."(3) That did not tell me very much, so I looked up his death certificate, which fortunately was more explicit--under "Cause of Death" the attending physician had written quite clearly "arsenic poisoning," which confirmed my suspicion of his method of specimen preparation. I passed this information on to the people who are responsible for the collection, and they are still considering what action to take.

Dangers of Arsenic Poisoning

Understanding the Risk: Toxic materials may be ingested by mouth, inhaled, or absorbed through the skin. They may irritate the eyes, nose, throat, or skin, causing tearing, sneezing, or a insect damage rash. They may cause nausea and vomiting. Certain materials can trigger a violent physical reaction or death within a short period of time. Some are especially dangerous in combination with other factors. Others cause long-term health consequences that may not be evident for many years. Museum personnel with allergies, respiratory or cardiac problems, or who are pregnant should exercise special caution about the amount of time spent in closed storage areas.(4)

The details of arsenic poisoning, and indeed the history of medical and social attitudes toward arsenic, are beyond the scope of this "Notebook." Suffice to say that over the years attitudes have changed. Writing about 120 years ago, one author said that although it "cannot be used with too great care, as it is a deadly poison[,]... Arsenic alone will sometimes poison slightly the wound with which it comes in contact, but no more than common salt." He said further that he had "been told repeatedly, by competent physicians, that the small quantity taken, wither by inhalation while using it, or by numerous other accidental ways, would be beneficial, rather that injurious ......”(5)

When it comes to working with specimens that were collected and preserved during the twentieth century, one is not necessarily home free. A prominent ornithologist published a Guide to Taxidermy in 1914 in which he said that "Arsenic used in the form of a soft soap ... is the best material known for the preservation of a bird's skin." He mentioned, however, the dangers of handling arsenic, especially "in the hands of careless or very ignorant per- sons," and suggested that one should "not use any of the family cooking utensils" when preparing arsenical soap.(6) In 1928 the manual, Trapping, Tanning and Taxidermy, instructed the taxidermist, after clearing his work place for action, to "place before you on the bench a pot of arsenical paste ...... Further, he says to "paint the skin all over on the inside with the arsenical paste."(7)

One twentieth-century taxidermist advocated substituting borax for arsenic, publishing his instructions in the 1940s.(8) Nevertheless, as recently as 1960, a mail-order school of taxidermy sent out lessons which called for the use of powdered arsenic and arsenical paste, in which arsenic is mixed with soap, and included full directions throughout the lessons for their use. And, it has been reported "that arsenic was still recommended for mammals as late as 1981 ... and was used on birds at the Smithsonian until the early 1970s."(9)

Obviously, great care must be taken when handling unfamiliar collections of natural history specimens. Although the toxicity of different arsenic compounds varies, even with small quantities, chronic poisoning can occur when arsenic is absorbed over a long period of time. Precautions should begin with gloves and standard hygienic procedures for the work place, and then can extend to dust masks and protective clothing as required. Eating food at one's desk should be stopped. Many museums now restrict snacking and eating to proper food facilities, if not for the sake of the curator, then at least to discourage small creatures that inevitably forage in buildings.

Help for the Curator

In trying to deal with this problem of hidden danger in the museum, the curator has available various analytical techniques for determining the presence of arsenic. Some involve sophisticated instrumental procedures that require skilled supervision. Others can be used by staff in a museum with modest facilities. In any case, curators may wish to consult with specialists in local morgues, schools, or universities in order to determine the best sources of information and help that are available in their own areas. For the museum with mostly or all volunteer staff, professional help definitely should be sought.

Workers at the Carnegie Museum of Natural History have reported a "simple and rapid wet-chemical test," which was developed for them by a research chemist at the University of Pittsburgh. They have used this test "extensively .. to screen specimens for the presence of arsenic," and describe it as being both "transportable" and useful in circumstances where laboratory facilities are not available, although they recommend that it "should be conducted in a well-ventilated area."(10) However, this test requires several dangerous chemicals and should be conducted only by a professionally qualified person. Hydrochloric acid and potassium hydroxide are used in the testing procedure and small amounts of the gas arsine are produced. If required, a research chemist or forensic specialist then can be called upon to test specimens more rigorously. A number of instrumental, analytical techniques are available for the specialist to use in looking for arsenic.

At the present time, collections managers at the Cincinnati Museum of Natural History use the Pittsburgh test with success and describe it as being "fairly simple to perform." Unfortunately, the test is destructive since it involves dissolving samples in potassium hydroxide, but the samples are small. They "may be powdery or crystalline residues from the object, dust collected by microvacuuming techniques, fragments of feathers or skin, and thread, hair or other fibers." Indeed, at the Carnegie Museum workers "have found that fibers cut from a cotton-tipped swab that has been dampened lightly with distilled water and touched on the surface of a specimen provides an excellent sample."

Arsenic, of course, is not the only chemical danger waiting for the unwary curator. Compounds of mercury were mentioned earlier. That old familiar presence in both anatomy laboratory and museum, formaldehyde, is treated with far greater respect today than even a couple of decades ago, and testing procedures are available to determine whether a person has had too much exposure. And heaven knows what potential trouble is contained in even a modest historical collection of pharmaceuticals.(11)

Fortuity is not always good, or even benign for that matter. To paraphrase a philosopher whose name I have forgotten, chance may favor the unprepared curator, but in such a way that she or he may not care for. If you do not know who mounted a natural history specimen and how it was prepared, then beware of any collection that includes hair, feathers, or dried flesh. When preservative solutions need to be replenished or replaced, seek the help of someone who truly knows and understands chemicals. Old collections often contain important specimens, so it is worth your while to be careful. But, "Be Careful." You must!

The Three Cs of Responsible Specimen Handling

Be CAUTIOUS as you approach unknown or uncertain specimens. Be CAREFUL as you handle those specimens. And be CONSCIENTIOUS as you deal with problems that may arise.

The Local History Notebook is edited and published by the Ohio Historical Society's Local History Office in order to bring useful information to people working in the local history field. The selection of subjects and authors is based on the OAHSM Editorial Board's and the Local History Office's determination of issues which are timely in nature and lasting in scope. The reference inserts are copyrighted 1993 by the Ohio Historical Society. Reprints are available; please specify volume and number. For further information, contact: