Two Kinds of Water
and their importance to living organisms

This web page is about the work of
Philippa Wiggins
retired from the Department of Medicine,
University of Auckland Medical School,
Auckland, New Zealand.

16th of July 1925 - 16th of March 2017.
An obituary may be found
at the bottom of this page

Philippa M Wiggins

Philippa Wiggins at Otago University in 1964
Published in University of Otago 150 years
The Hocken Collections, Department of Biochemistry records, MS-4113/009, S14.512b. Permission applied for.

In 1986 Dr Wiggins published the results of her experiments showing that water exists in two distinct structural forms. She used infrared spectroscopy to study the strength of hydrogen bonding in water trapped in membranes. This showed two distinct bond strengths instead of the wide range of bond strengths that would be expected for a single type of water structure (Wiggins and van Ryn,1986).

Recently a group of scientists using the synchrotron at Stanford University, and other groups in Japan and Sweden, showed that liquid water exists simultaneously in two forms. This finally gives independent solid support for a theory which Dr Wiggins proposed many years ago to explain the behavior of water in biological systems. (See the Stanford News article by Tuttle, and the scientific publication by Huang et. al., Aug 2009 given in the reference list below.)

Dr Wiggins has spent most of her life studying the properties of water. She started out as a physical chemist and discovered that silica gel was capable of selectively taking up potassium and excluding sodium (Wiggins 1973). In fact the absorption of ions into water trapped in tiny cavities or pores inside the silica gel followed the same pattern as the selective uptake of ions in living cells, following the order   Mg2+ <   Ca2+ <   Li+ <   Na+ <   K+ <   Rb+ <   Cs+.    She proposed that the structure of water inside these pores was different to bulk water and that it behaved as a different solvent, taking up potassium in preference to sodium.

This discovery led in the mid-1970s to her proposal that the sodium-potassium ATP-ase, known as the sodium pump, operated by forming a pocket of 'ordered' water at the same time as a channel openned in the ATP-ase. This allowed solutes such as sodium to diffuse out of the pocket of 'ordered' water, through the channel, into the bulk water outside the cell. The channel closed as the ordered water collapsed and the conformational structure of the ATP-ase also changed. This model has required only minor refinements as more is learned about the actual protein stuctures of these pumps and about the properties of water.

The discovery that water exists in two structural forms led to the gradual development and evolution of a theory which explains many previously unexplained phenomena in biology. The wide range of biological processes that can be explained by this theory, ranges from how the sodium-potassium pump and other pumps work; how enzymes work to catalyze chemical reactions which would otherwise require extremely high temperatures and pressures; how proteins fold (Wiggins, 2009a) or in some cases misfold causing diseases such as Alzheimers Disease, Parkinson's Disease and Huntington's Disease; how prion diseases such as Creutzfeldt-Jakob Disease and "mad cow disease" occur (Wiggins, 2008a); how DNA spirals into such an elegant double helix and how certain crucial steps in the origins of life may have occurred.

She is a meticulous laboratory worker and an honest scientist dedicated only to discovering the truth about water and its role in all living things, while avoiding politics and publicity. She has numerous publications in peer reviewed journals, and for the list of references below she has selected a handful of articles that were written after 1986 when she confirmed that water exists in two forms. At that time all her work had focused on the properties of water near surfaces or in small cavities. In 1994 Wilse Robinson proposed that bulk liquid water also existed in two forms and called it 'The Modern Mixture Model' to distinguish it from an older model apparently proposed by Roentgen in 1891. Since 1994 Dr Wiggins' work has incorporated the modern mixture model into all her publications and her recent contribution has been to explain the importance of these discoveries to biological systems and to explain the thermodynamics of the equilibrium between two structural forms of water.

Wiggins' theory is based on the idea that all water exists in two forms. One is an ice-like structure called low density water or LDW, and she has shown that it's infrared spectrum is indeed similar to ice, while the high density water (HDW) has a different and clearly distinct infrared spectrum. Bulk liquid water has a mixture of these two types of water kept in an equilibrium by an interesting energy balance described by thermodynamics. It is a balance between entropy (or randomness) and enthalpy (or heat) in the two kinds of water. This balance shifts with increasing temperature with more water shifting from LDW to HDW. The balance between these two forms of water is affected by the properties of nearby surfaces and solutes. Dr Wiggins has carefully studied the free energy changes that occur in various situations and this analysis has proven remarkably powerful in explaining numerous anomolies that have puzzled chemists and biologists for a century or more.

The reader may be interested in a free on-line monograph Dr Wiggins wrote in 2007 called Life Depends upon Two Kinds of Water. This and other references with links to web sites containing abstracts or full publications are listed below.

A. Evan Lewis PhD, MD (previously a PhD student of Dr Wiggins from 1974-1977)

NEWS FLASH June 2018

A news report describes experiments demonstrating that "Water exists in two forms". The article is based on a publication in Nature which describes two forms of isolated water molecules in a vacuum. It was found that the nuclear spins of the two hydrogen nuclei can be either in the same direction or oposite directions and this results in a 23% difference in the rate of a chemical reaction. Could this finding be related to the differences in hydrogen bonding in high density and low density water?

Another article in the popular press Water Behaves Differently From All Other Liquids, And We Finally Know Why introduces research showing that the anomolous behaviour of water can be explained by proposing that water forms specific tetrahedral structures similar to diamond in some regions while remaining more disordered in other regions. The proportion of water in each of the two states can change, resulting in the anomolous behaviour. The full article by John Russo et al, published in PNAS on 2nd April 2018, can be found here: Water-like anomolies as a function of tetrahedrality. The bond angles between hydrogen and oxygen promote the formation of tetrahedral structures with hydrogen bonding. Professor Wiggins' early work referred to the two kinds of water as ordered and disordered, structured or unstructured but later she preferred the terms low density and high density structures.

Martin Chaplin of London South Bank University has compiled an amazing on-line monograph called 'Water Structure and Science' which gives a thorough overview of all aspects concerning the properties of water.


Cameron I.L., Kanal, K.M., Keener, C.R. & Fullerton, G.D. A mechanistic view of the non-ideal osmotic and motional behavior of intracellular water. Cell Biol. International 21 (1997) 99-113.

Cho, H.C., Singh, S. & Robinson, G.W. Understanding all of water's anomalies with a non-local potential. J. Chem. Phys. 107 (1997) 7979-7988.

Evan A, Lewis D, Wiggins PM A simple universal mechanism of use and conservation of energy: its application to movements of ions and other materials across cell, mitochondrial and other membranes and to oxidative phosphorylation. Med Hypotheses. 1977 Jan-Feb;3(1):25-32

The above reference was published with the authors listed incorrectly. It should be A Evan Lewis and PM Wiggins. Please contact me at the email address given below if you would like the full article.

Harrington, S,. Poole, P H Sciortino,F and Stanley, H. E. Equation of State of Supercooled SPC/E Water. J. Chem. Phys. 107, 7443-7450 (1997)

Huang, C, K. T. Wikfeldt, T. Tokushima, D. Nordlund, Y. Harada, U. Bergmann, M. Niebuhr, T. M. Weiss, Y. Horikawa, M. Leetmaa, M. P. Ljungberg, O. Takahashi, A. Lenz, L. Ojamäe, A. P. Lyubartsev, S. Shin, L. G. M. Pettersson and A. Nilsson. The inhomogeneous structure of water at ambient conditions. Proceedings of the National Academy of Sciences, August 13, 2009, doi: 10.1073/pnas.0904743106

Jason K. Holt, Hyung Gyu Park, Yinmin Wang, Michael Stadermann, Alexander B. Artyukhin, Costas P. Grigoropoulos, Aleksandr Noy, Olgica Bakajin Fast Mass Transport Through Sub-2-Nanometer Carbon Nanotubes. Science 19 May 2006: Vol. 312 no. 5776, pp. 1034 - 1037 (

Mishima, O. & Stanley, H.E. Decompression induced melting of ice iv and the liquid-liquid transition in water. Nature (Lond.) 392 (1998) 164-168.

Mishima, O. & Stanley, H.E. (1998): The relationship between liquid, supercooled and glassy water. Nature (Lond.) 396 (1998) 329-335.

Ridley, M, 2000. Mendelae's Demon. Phoenix, London.

Robinson, G. Wilse (1996) Water in biology, chemistry, and physics: experimental overviews and computational methodologies. World Scientific Series in Contemporary Chemical Physics, Vol 9. World Scientific Publishing Company,Pte Ltd, PO Box 128, Farrer Rd, Singapore 912805.

Tuttle, Kelen. SLAC researchers reveal the internal dance of water, Stanford University News Aug 10, 2009.

Vedamuthu, M., Singh, S. & Robinson, G.W. Properties of liquid water: origin of the density anomalies. J. Phys. Chem. 98 (1994) 2222-2230.

Wiggins, P.M (1973). Ionic partition between surface and bulk phase water in silica gel. Biophysical J. (1973) 13, 131-146.

Wiggins, P.M. & van Ryn, R.T. (1986) The solvent properties of water in desalination membranes. J.Macromol. Sci. Chem. A23 (1986) 875-903.

Wiggins, PM (1995) Microosmosis, a chaotic phenomenon of water and solutes in gels. Langmuir 11 1984-1986.

Wiggins PM. (2002a) Water in complex environments such as living cells. Physica A 314: 485-491.

Wiggins PM (2002b) Enzymes and two-state water. J.Biol.Physics and Chemistry 2: 25-37.

Wiggins P (2007) Life Depends upon Two Kinds of Water. PLoS ONE 3(1): e1406. doi:10.1371/journal.pone.0001406

Wiggins PM (2008a) Prions plaques and polyelectrolytes. Journal of Biological Physics and Chemistry 8 49-54

Wiggins PM (2008b) DNA as a Darwinian self-replicator. Journal of Biological Physics and Chemistry 8 89-93

Wiggins PM (2009a) The source of some of the extraordinary powers and properties of enzymes. WATER 1, 35 - 41

Wiggins PM (2009b) Enzymes and surface water, WATER 1, 42 - 51

For a more comprehensive list of publications by Philippa Wiggins go to the following site and enter Wiggins PM.

Search PubMed.


A. Evan Lewis - DrEvanLewis at

First Posted: December 10th 2009.

Last Updated: June 6 2018.


Obituary Draft
Philippa Wiggins the unsung scientist.

Professor Philippa Wiggins passed away peacefully on March 16th 2017.
Born on 16th of July 1925 she was 91 years old.

Professor Philippa Wiggins (nee Glasgow) was a very private and modest person but in reality she was a widely recognized and respected scientist who was known around the world for the huge impact she had on our basic understanding of the biochemistry of life. When I told her she should be a candidate for the Nobel Prize in Medicine and Physiology she said she was not interested in that.

Specifically her contributions to understanding the special properties of water, in living systems, would be difficult to over-estimate. She worked tirelessly as a particularly careful and meticulous research scientist and taught a number of young post-graduate researchers. She was a master of the English language and through thesis supervision she passed this skill on to her pupils.

She was appointed Professor of Membrane Physiology at the Medical School in the University of Auckland and later Emeritus Professor. She received numerous awards and accolades but due to her modest, private, and unassuming nature, these often went unnoticed. Her work resulted in at least 70 articles published in respected international peer-reviewed journals. Later in her life, she worked with companies in New Zealand developing industrial and medical applications of her theories and had about 40 patents to her name.

She was able to explain many phenomena by more fully understanding the structure and properties of water. She realised that water is not a random collection of H2O molecules with little interaction between the molecules or those dissolved in it. It was already known that water is unique in being an extremely polar molecule which means that the two hydrogen atoms have a strong positive charge while the single oxygen atom carries a strong negative charge. This results in water molecules being strongly attracted to each other with connections called hydrogen bonds.

Through this bonding, water can form huge crystal-like structures similar to ice that have a lower density than the surrounding less-structured water. One might expect this to cause water to become solid, and it does at low temperatures. But at temperatures above zero degrees C, the ice-like structures break down and form again at incredibly rapid speeds. This gives liquid water its special properties. Without hydrogen bonding there would be only solid and gas but no liquid. Interestingly, these two forms of water which co-exist have different chemical properties.

The low density crystal-like structures take up potassium but not sodium. Dr Wiggins first observed this phenomenon in the late 1960s and early 1970s when she was studying the physical chemistry of silica gel at the University of Otago. This material contains tiny pores or holes that are so small that huge water structures cannot form and water exists only in the low density structured form. Consequently, the water in silica gel takes up potassium and excludes sodium.

A “eureka moment” occurred when she realised that this is exactly the way living cells work. When she analyzed other chemical ions they also behaved exactly the same way as living cells. To explain this, she proposed that water can exist in at least two different forms as described above and that the living cells make use of this property. She used infrared spectroscopy to demonstrate the existence of two structures of water in biological systems, and this has been confirmed in bulk water using the linear accelerator at Stanford University by other researchers.

Professor Wiggins’ discovery has had a profound impact on many branches of biochemistry and medicine. She has published papers describing how water affects the structure of DNA and proteins and how it has influenced the evolution of life itself. Since these interactions are fundamental to life, they can also explain several types of diseases. She wrote about how prions cause diseases like mad cow disease and how water influences the formation of plaques in the brain that cause Alzheimer’s disease.

This short article cannot describe all the things that Philippa did to advance our understanding of water and life itself, but the serious reader is referred to a web site that includes links to many of her scientific publications,

After gaining an MSc honors degree in Chemistry at Canterbury University in 1947, Philippa was awarded a scholarship to work at the Davy-Faraday Laboratory at the Royal Institution in London, and later completed her PhD at King’s College’ London. Philippa returned to New Zealand to work with Dr Walter Metcalf at the University of Canterbury (who was also my teacher and PhD examiner). From 1962 to 1966. She then worked as a research scientist at the University of Otago and that is where her lifetime interest in the role of water in living cells began.

During times when it was difficult to obtain funding for scientific research and when grants were usually for two years, she was awarded lifetime funding as a Career Fellow by the New Zealand Medical Research Council. She continued her research at the University of Auckland from 1970 to 1990. In 1994 she was cofounder of BioStore NZ, and in 1997 she was a research scientist for Genesis Research and Development Corporation. She continued to publish scientific papers until at least 2009.

For all the people who knew Philippa in her professional roles, her passing is a time of great sadness at the loss of such an important scientist and such a wonderful personality. Our condolences go to her family who must also feel a great sense of loss. She certainly would have been proud of her grandson, Jordan Douglas who is embarking on a PhD in computational biology at the University of Auckland, and thus continuing the family tradition.

Written by Evan Lewis, PhD, MD who was one of Professor Wiggins’ PhD students 1974 to 1978.