Perhaps these references will help - I think the proposed immersion method sounds a bit messy!

		Lam, Y. M., Xingbin Chen, C. W. Marean, C. J. Frey. 1998. Bone Density and Long Bone Representation in Archaeological Faunas: Comparing Results from CT and Photon Densitometry. J.A.S.

		Lam, Y., Pearson, O.M., Marean, C.W, Chen, X. 2003. Bone density studies in zooarchaeology. Journal of Archaeological Science 30:1701-1708.

Prof. Ariane Burke, 
Dept. d'anthropologie, 
Université de Montréal, 
C.P. 6128,  Succursale Centre-Ville 
Montreal, QC 
Canada,  H3C 3J7 
Tel. 514-343-6574 Fax. 514-343-2494
http://www.mapageweb.umontreal.ca/burkea/

________________________________

From: Analysis of animal remains from archaeological sites on behalf of [log in to unmask]
Sent: Wed 2009-11-18 8:46 PM
To: [log in to unmask]
Subject: Re: [ZOOARCH] Bone density study by submerging in water



I actually did a bone-density study back in my Smithsonian days, because I
wanted to prove to breeders of Arabian horses that a common myth they hold
is false -- i.e. that Arabians have 'denser bone' and it is therefore OK
for them to have limbs less substantial than considered normal in other
breeds or in wild/feral equines. To do this I looked at cannon bones for a
wide array of breeds. I built an overflow apparatus and toted that and a
scale up to the attic where the skeletons are stored. First I weighed each
the bone, then tied a fine thread around it and slowly dunked it into the
bucket with the overflow tubing, which emptied into a big graduated
cylinder. You do need to plug foraminae with a bit of wax first. The
object, as Greg points out, is to get the density which is mass per unit
volume and this little study gave very neat results.

If you are working with small bones, i.e. rodents and such, then you're
going to come up against the surface tension of the water -- just add soap
and that should fix it so they sink nicely. I am sure, too, that a good
hand could build a small water overflow apparatus that would be accurate
enough to determine whether the bones are at, above, or below normal
limits for density. I like the sand idea but I think if the specimens are
very small one would almost have to do this with water (the smaller the
specimen, the more the 'particle' size of the medium is going to matter).

As to wetting the bones causing 'irrepairable damage': I don't know how
that could be a problem. Most of the skeletons in museum osteological
collections that were cataloged prior to WWII were prepared by wet
maceration and many, both large and small species, are still done that way
today. I do all mine that way (rather than maintaining a bug colony). And
not only are they wet the whole time they're in the maceration barrel,
when they come out of there they get a few hours in a pot set to simmer
with some nice industrial-strength ammonia, detergent, and a dash of lye.
That is followed by a nice little peroxide rinse to make 'em pretty. This
is my teaching collection, you understand; I don't expect anybody to be
wanting to do DNA on that, and maybe if you did you would have to worry
about all these chemicals. All I want is for 'em to smell tolerable and
not be greasy for my students in lab class. Cheers -- Dr. Deb


> Hi, I have just a couple of observations - many of my skeletons still
> contain some oil residues, sometimes quite a lot, use of bones that
> might look 'clean' outside might not give a good result, also is 72
> hours enough to naturally air dry a big bone completely?
>
> On 18/11/2009 17:15, Teresa Steele wrote:
>> Thought that there might be more people on this list-serve who can help
>> than the
>> mammalogy list-serve...
>>
>> Dear Mammal-L, specifically folks with mammal collections:
>>
>> Have any of you loaned bone elements for bone density studies?  I have
>> an interesting
>> request for some mammal bones, and the researchers would like to use the
>> following
>> protocol:
>>
>> "Element density will then be calculated by water immersion. Each
>> element will be
>> soaked in water until saturated (this has been taking less than 72 hours
>> for the specimens
>> we have used to date). Then the element is weighed whilst submerged,
>> suspended in a
>> sling or on a platform on a balance accurate to
>> 0.0001g. The specimens are then left for a further 72 hours to air dry
>> at 72F placed on
>> paper towel. After this, the specimens are weighed again, this time in
>> air. Comparison
>> between the two weights and the weight of the measuring apparatus allows
>> for the
>> accurate calculation of bone density. This method has provided accurate,
>> repeatable
>> density measurements for the 10 taxa that have been measured so far. No
>> other
>> methodology is able to measure bone density of such small elements with
>> the required
>> degree of accuracy."
>>
>> My concern is that water immersion of the bone may cause irreparable
>> damage (although
>> I think the study is an interesting one and worthy of a loan).  Please
>> reply directly to me
>> ([log in to unmask]) if any of you has had experience with this type of
>> methodology and/or
>> might have some insight as to what to expect in terms of bone quality
>> after an extended
>> water immersion.
>> Many thanks,
>> Jessica
>>
>> -- Jessica E. Light
>> Assistant Professor and Curator of Mammals
>> Department of Wildlife and Fisheries Sciences
>> Texas Cooperative Wildlife Collection
>> Texas A&M University
>> 210 Nagle Hall, 2258 TAMUS (mailing)
>> 320A Heep Laboratory Building (office)
>> College Station, TX 77843
>> Phone: 979-458-4357
>> Fax: 979-845-4096
>> email: [log in to unmask]
>> http://wfsc.tamu.edu/lightlab
>>
>>
>
> --
> SH-D ArchaeoZoology
> http://www.shd-archzoo.co.uk <http://www.shd-archzoo.co.uk/> 
>
>
>