Comparative chemical investigations of alum treated archaeological wood from various museum collections

Heritage Science

Table 1 Sample names, treatment, additives listed in treatment records and surface pH values

Collection	Sample	Wood type^c	Sampled area	Treatment/additives noted in laboratory reports	pH^a
Dejbjerg, (D) treated in 1883, National Museum of Denmark, Copenhagen (Denmark)	D-A1624	Diffuse porous HW	Outer	Alum	3.0
	D-B1624	Ring porous HW	Outer	Alum	2.0
	D-C1628	Diffuse porous HW	Outer	Alum	3.0
	D-D1626-A	Ring porous HW	Inner core	Alum	3.5
	D-D1626-B	Ring porous HW	Outer	Alum	3.5
	D-E1622-A	Ring porous HW	Inner core	Alum	3.5
	D-E1622-B	Ring porous HW	Outer	Alum	4.0
	D-F1629	Diffuse porous	Outer	Alum	3.5
Oseberg (N) treated between 1904 and 1913 Museum of Cultural History, Oslo (Norway)	N-187D	HW	Dark part	Alum	1.5
	N-187L	HW	Light part	Alum	1.5
	N-207-A	Diffuse porous HW	Inner core	Alum, linseed oil	2.5
	N-207-B	Diffuse porous HW	Outer	Alum, linseed oil	2.5
	N-250F	Diffuse porous HW	Middle	Alum	1.5
	N-250K	Diffuse porous HW	Inner alum-poor	Alum	2.5
Glimmingehus (S) treated in 1936 Swedish History Museum, (Sweden)	S-5T	HW	Outer	Alum, linseed oil	3.0
	S-125h	HW	Outer	Alum, retreated with PEG^b	4.5
	S-125k	HW	Outer	Alum	3.5
	S-346	HW	Outer	Alum, glycerol, linseed oil retreated with PEG^b	4.5
	S-346d	SW	Outer	Alum	2.5
	S-346e	SW	Outer	Alum	2.5
	S-383	HW	Outer	Alum, linseed oil, glycerol	1.5
	S-383c	HW	Outer	Alum, linseed oil, glycerol	1.5
Reference archaeological	Head post N-124	Maple	Inner core	Untreated	–
	Finest sled pull N-17	Maple	Inner core	Untreated	–
	Arch pine	Pine	Inner core	Untreated	–
Reference fresh undegraded	Ref. maple	Maple		Untreated	–
	Ref. birch	Birch		Untreated	–
	Ref. pine	Pine		Untreated	–

^aSurface pH measurements were taken directly on object surfaces by applying damp pH strips. pH of reference sound maple is 5.5. pH for samples head post N-124 and finest sled pull N-17 was not measured
^bSamples were re-treated with PEG 2000 between 2005 and 2009
^cThe wood genus is included only when it is confirmed by light microscopy. Hard wood is abbreviated as HW. Softwood is abbreviated as SW