Answer by Researcher byrd on Tue 19 May 2009 - 1:54 am UTC:

Dear Bryan, 

Many thanks for your patience and understanding regarding my time conflict
and resultant delay in answering your question. 

You will be interested to know that this particular hypothesis, i.e. that
Dr. Crippen might have used acid in the bathtub to dispose of his wife's
body, is definitely within the realm of possibility. As a matter of fact
there is precedent in the use of acid to dispose of a dead body. I refer
primarily to the case mentioned to in the GA question you provided a link
to in your previous comment, also referred to by Myoarin in his comment. 

This, of course, is the well-known case of John George Haigh, a famous
20th-century British serial murderer who disposed of the bodies of his
victims by dissolving them in sulfuric acid. According to Wikipedia, "He
was convicted of the murders of six people, although he claimed to have
killed a total of nine, dissolving their bodies in concentrated sulphuric
acid." The case is referred to as "The Acid Bath Murders." 

However, Haigh was convicted partly based on forensic evidence which
included a few fragments of bone and some gallstones that had not
dissolved. Perhaps they might have, had they been left in the acid a little
longer. The body of the woman which led to his arrest and ultimate
conviction was left in the acid for two days as noted. Maybe three days
would have done it. I was unable to locate any precise instructions as to
exact length of time to soak a body, but I would think another day or two
might have taken care of those undissolved bits. 

In addition to the undissolved biological remnants found by the police, the
unfortunate woman's dentures also remained, so anyone implementing this
method of disposal would need to be aware of and be sure to remove any non-
or potentially non-dissoluble elements. However, presumably a doctor, with
a scientific education and, in the case of Dr. Crippen, pharmaceutical
experience as well, would have been aware of the chemical properties of
acid, particularly one so well-known as sulfuric, even though not with the
level of detail which we in the 21st century posess. 

Here is a very complete account of Haigh's murderous activities, including
descriptions of his early experiments on small rodents, as well as details
of what did and did not dissolve in the acid:
http://mypchem.com/myp8/myp8c/myp8c_htm/U2_a&b/acid_bath.htm 

The body of another more recent murder victim was also allegedly disposed
of by being dissolved in acid, though this one was never proved. Still,
it's interesting to read the news saying that the alleged perpetrator,
Charles Carneglia, a U.S. gangster associated with mob boss John Gotti, had
told someone else about it, saying that acid was "the best method to avoid
detection." 
http://www.foxnews.com/story/0,2933,478124,00.html 

Another, even more recent case, involves the confession of Santiago Meza
Lopez, an associate of a Mexican drug lord, who confessed in January of
this year to disposing of up to 300 bodies over several years by dissolving
them in barrels of acid. However, in this case, they were apparently in a
hurry and so did not let the bodies completely dissolve as Meza said he
also buried the remains. See the news report, here: 
http://tinyurl.com/pazout

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In addition to the question of time required for complete dissolution,
there is also the matter of volume of acid required. Clearly the body would
have to be submerged in the acid for it to dissolve. So the question seems
to be how much the bathtub could hold less the displaced volume of the
body. 

An average bathtub can hold anywhere from 150-200 litres (about 39-52
gallons) of water. Dr. Crippen's wife's weight of 170 lbs. (
http://uclue.com/?xq=2950 ) would be in volume approximately equivalent to
77 fluid litres (20 gallons). So, with the entire body in the bath, it
would take approximately 73-123 litres (19-32 gallons) of sulfuric acid to
fill the tub to the top. However, the could have been quite dangerous to
the Doctor and the floor, so I'd subtract some to bring the level down
below the rim. Of course, if parts of the body were missing already, having
been disposed of some other way, correspondingly less volume of acid would
be required to submerge the remaining parts.
http://www.essentialbathrooms.co.uk/?search=baths 
http://www.bathroomheaven.com/sp_showitem/2469 
http://www.calculateme.com/Volume/Liters/ToGallons.htm 
http://www.convert-me.com/en/convert/weight2volume 

Regarding the question of availability, Haigh bought his acid in 10-gallon
carboys, which are large, narrow-necked glass bottles. Three full ones and
one empty were discovered in his residence during the police investigation,
so apparently there was no problem, at least at that time, in obtaining
large containers of acid. I would think a doctor would have no difficulty
in locating sources, and also might be more rather than less likely than
the average citizen to be able to make such a purchase openly. The fact
that he worked for a pharmaceutical company would lend even greater
credence to his ability to obtain chemicals of various sorts. 
http://www.bottlebooks.com/demijohn/big_bottles_big_history_demijohn.htm
http://www.weekendbrewer.com/carboysfermenters.htm

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Which acid would have been best for such purpose? Ordinary sulfuric acid
(H2SO4) which is what Haigh used, would have done the job and would also
have been available at the time Dr. Crippen may have had need of it. The
other so-called "strong acids" include HCl - hydrochloric acid (HCl),
hydrobromic acid (HBr), hydroiodic acid (HI), perchloric acid (HClO4), and
nitric acid (HNO3). Dorian Gray used nitric acid, which is plausible also
given its presence on this list of strongest acids.
http://chemistry.about.com/od/acidsbases/a/strengthacids.htm

Guidelines for handling sulfuric acid from Stanford University say that it
will attack the enamel of the teeth, further support for its use for the
purpose under discussion. In fact, the International Chemical Safety Card
for this says there is "Risk of tooth erosion upon repeated or prolonged
exposure to an aerosol of this substance." Clearly the Doctor would have
had to cover his nose and mouth while filling/unfilling the tub had he
chosen this method of disposal.
http://tinyurl.com/pasat2
http://www.cdc.gov/niosh/ipcsneng/neng0362.html

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Just for interest's sake, I'll mention that another substance possibly
useful for the purpose at hand could have been lye, a base, on the opposite
end of the PH scale from acid. Lye, or sodium hydroxide (NaOH) has been
used in the past to dispose of roadkill or dead farm animals. According to
Wikipedia, "This process involves the placing of a carcass into a sealed
chamber, which then puts the carcass in a mixture of sodium hydroxide and
water, which breaks chemical bonds keeping the body intact. This eventually
turns the body into a coffee-like liquid, and the only solid that remains
are bone hulls, which could be crushed between one's fingertips."
http://en.wikipedia.org/wiki/Sodium_hydroxide

Apparently some murderers have also used lye to aid in the disposal of
their victims' bodies. One such was Belle Gunness who, with her lover, was
accused of murdering over fifty people in Indiana in the 19th century.
Investigators found dismembered bodies "wrapped in gunny sacks doused with
lye." Of course, these were not completely dissolved but might have been
had she used proper technique. Lye also, of course, would have been readily
available in Dr. Crippen's day, perhaps even more so than acid. 

Just as an interesting aside, alkaline hydrolysis, or the dissolving of
tissue using a strong base such as lye, is being proposed currently as an
alternative method of disposal of organic remains, including human remains.
Because the process involves high heat and pressure, this would not have
been possible for Dr. Crippen, but thought you'd like to read about it
anyway:  
http://www.msnbc.msn.com/id/24526431/ 

Here is more technical information about the process:
http://www.alnmag.com/articles.asp?pid=76

The commercial kind of alkaline hydrolysis has been named, "Resomation."
Here's a site you can visit for more information:
http://www.resomation.com/

And here's an interesting article about other practical uses for alkaline
hydrolysis: http://tinyurl.com/rd5qcl 


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In conclusion, I would reiterate that the dissolution of the body, or part
of the body, in a bathtub using acid is a relatively plausible hypothesis
for explaining how Dr. Crippen may have disposed of his deceased wife's
body, or parts thereof so that some parts of her were never found.  

I hope you will find the information helpful. If you require additional
assistance, please do Request a Clarification and I will be happy to
respond. 

Best regards, 

Byrd