THE METALLURGY OF THE NAHAL MISHMAR HOARD RECONSIDERED

The Nahal Mishmar hoard, found in a cave in the Judean Desert in 1961, is a key find for the study of Chalcolithic metallurgy in Israel and the Levant. Recent analyses of Chalcolithic metalwork from sites such as Shiqmim in Israel raised doubts about the validity of published analyses from the hoard. Accordingly a programme of re-analysis was established using atomic absorption spectrometry and electron probe microanalysis. The new analyses confirmed the doubts and showed that the metallurgy of Nahal Mishmar was the same as that at the other sites. The alloys used for the cast products in the hoard were generally ternary arsenic-antimony copper alloys with up to 20% alloy content; less common were compositions with arsenic and nickel. The unusual metallography of these alloys is described. Some suggestions are offered as to the mode of manufacture of the alloys.     

SCIENTIFIC ANALYSIS OF ROMAN GLASS FROM AUGUSTA PRAETORIA

Fifty-five fragments of Roman glass from Augusta Praetoria (Aosta, Italy) were analysed by inductively coupled plasma optical emission spectroscopy determining 15 elements (Si, Na, Ca, Al, Fe, Mg, Mn, Ti, Sr, Ba, Cr, Ni, Cu, Co and Pb) on dissolved samples; in addition, potassium was determined by flame atomic absorption spectroscopy. The analytical results indicate that all the fragments, with one exception, are silica-soda-lime glasses; (he exception is a potash glass. Cluster analysis was performed on the analytical data by accounting for either 14 (all the elements searched for but Ni and Pb) or eight elements (after further removal of Si, Fe, Mn, Cr, Cu and Co from the data set). The results obtained indicate that, once colouring and decolouring agents are removed, the classification of the glasses seems to be mainly determined by chronology; separate groups within coeval fragments may indicate different provenances.     

A BRONZE SCULPTURE ATTRIBUTED TO LOUIS-SIMON BOIZOT AND PLATINUM COATING METHODS

During the examination of the sculpture of Medea Rejuvenating Aeson attributed to Louis-Simon Boizot (1743–1809), X-ray fluorescence analysis revealed, surprisingly, that the outer surface of the brass cast was patinated with platinum. Research into the history of platinum coating methods revealed that chemical techniques for the deposition of platinum from solution were in use before the advent of electroplating. Some experimental work to replicate the patination technique of electrochemical replacement plating of platinum based on recipes from the nineteenth century is described. The technical evidence suggests that a late eighteenth-century date for the sculpture is reasonable.     

COMPOSITIONAL VARIABILITY IN COLOURLESS ROMAN VESSEL GLASS

A statistical re-analysis is undertaken of 118 inductively coupled plasma spectrometry analyses of Romano-British glass specimens found in excavations at Colchester. There are four vessel types present, some of which are associated with chronologically distinct periods. Previous research has suggested little difference in the mean composition of different types. The present paper shows that there are interesting differences in the variation of compositions within types, with some showing much greater compositional stability then others. Some possible models to explain this phenomenon are discussed.     

Roman Glazed Ceramics in the Western Mediterranean: Chemical Characterization by Inductively Coupled Plasma Atomic Emission Spectrometry of Ceramic Bodies

Several objects of Roman lead-glazed ceramic, found inHispania(Spain), were sampled and analysed in order to characterize them to study the spread of glazed ceramic in the western Mediterranean. Chemical analyses were carried out by Inductively Coupled Plasma Atomic Emission Spectrometry.Studies of the chemical composition of the ceramic bodies indicate that ceramics from two different production centres reachedHispaniaduring the Roman period: a non-calcareous fabric, coming from Lyon workshops, and calcareous bodies with bicoloured glazes from another main production centre, which is suggested to be Italy. Other objects, of central Gaulish or eastern origin, have also been found in the western Mediterranean, but only occasionally.     

BLOOD AS A BINDING MEDIUM IN A CHUMASH INDIAN PIGMENT CAKE

As part of a study of Chumash Indian pigments, some black pigment cakes have been examined. One pigment cake was characterized as soot by polarized light microscopy, and Fourier transform infrared microscopy showed that the binder was proteinaceous. Protein determination was followed by examination using gas chromatography-mass spectrometry analysis which showed a characteristic suite of amino acids to be present, proportionally similar to blood. The blood identification was confirmed by immunological analysis. The binder was shown to be a mixture of human and animal blood, the animal being pronghorn antelope. This is the first successful identification of a binding medium from a Chumash Indian pigment cake.     

ON SOME PHYSICAL CHARACTERISTICS OF CHINESE AND EUROPEAN RED WARES

When in the seventeenth and eighteenth century Chinese red ware from Yixing was imported into Europe, imitations of that ware, some of them delusively similar to the originals, were made in the Netherlands, Saxony, and England. With non-destructive energy dispersive X-ray fluorescence analysis (ED-XFA) the Chinese and different European red wares can be easily separated by comparing the patterns of their calcium oxide, manganese oxide, and lead contents. They also have density characteristics of their own.     

THE PETRALONA HOMINID SITE: URANIUM-SERIES RE-ANALYSIS OF ‘LAYER 10’CALCITE AND ASSSOCIATED PALAEOMAGNETIC ANALYSES

Separate sublayers of the ‘layer 10’calcite from the Mausoleum of Petralona Cave, Greece, have been re-analysed by Uranium-series and palaeomagnetic methods. The results confirm earlier findings that the whole of layer 10 represents a long time span, from about 160 ka to more than 350 ka, the latter being the dating limit of the U-series method using alpha-spectrometry. The minimum age refers to the upper brown sublayer that is now believed to correspond directly to the brown calcite that cemented the hominid skull to the adjacent cave wall; there was too little of the skull calcite to date directly by alpha-spectrometry. The age shifts caused by making corrections for the amount of detritus in the sublayer are effectively insensitive to assumed initial values of the amount of common ²³⁰Th present. Consequently, the minimum age estimate for the skull is about 160 ka, in approximate agreement with several earlier estimates. Palaeomagnetic analyses of ‘layer 10’and underlying sedimentary layers showed that the magnetization is unstable and cannot be used as a basis for age control in the Mausoleum.     

THE OPAQUE RED GLASS OF CELTIC ENAMELS FROM CONTINENTAL EUROPE

Opaque red glass was used in the Celtic world for enamels and inlays. Forty artefacts, of various dates and found in various places, have been sampled and studied. They all belong to the same type, a soda-lime-silica high lead glass coloured by crystals of cuprous oxide. There is only one subgroup: glass lumps from the Mont-Beuvray oppidum contain manganese, less iron, and less lead. This change could be the result of Roman influence. Although most of these glasses form a surprisingly homogeneous group, no conclusions as to their origin can be inferred from our present knowledge.     

STATISTICAL ANALYSIS OF CHEMICAL COMPOSITIONAL DATA AND THE COMPARISON OF ANALYSES

Recent statistical work on approaches to analysing compositional data - where variables sum to a constant for each row of a data matrix - may encounter difficulties when applied to data of the kind typically arising in scientific archaeology. The reason is that results obtained may be unsatisfactory from a substantive viewpoint for identifiable technical reasons. This paper explores and illustrates some possible resolutions of the problem. A feature of the approach used is to analyse subsets of the variables on separate scales. A synthesis of the results obtained from separate analyses is essential and the use of multiple correspondence analysis for this purpose is illustrated.