Can Habur Limestone curdle milk?

Abstract

Rajasthan has a fascinating array of rocks and minerals, one of which is fossil-rich Habur limestone (also referred to as Abur limestone1), named after the village Habur (27°19¢N : 70°33¢E). This rock is considered
of lower Cretaceous–Aptian age1, which makes it 125–112 million years old2. The brown coloured, ferruginous claybearinglimestone is rich in small fossils that give it a unique, eye-catching calligraphic
texture. Recently, a sample of this limestone was sent to us to find out what makes it curdle milk, as reported by people in the villages of Jaisalmer area, Rajasthan.

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CURRENT SCIENCE, VOL. 89, NO. 5, 10 SEPTEMBER 2005 729
Of course, as pointed out by Dharma-
palan, there may be one or two shortcom-
ings. However, considering the overall
health of higher education in India, every
institution has the responsibility to take
these acid tests. NAAC has made it man-
datory for accredited colleges to establish a
quality advisory committee and an internal
quality assurance cell to monitor qualita-
tive growth of the institution. Accredited
institutions are expected to submit annual
quality assurance reports.
I do agree that several libraries in our
state-affiliated colleges run without librari-
ans and are understaffed. Similarly, the de-
partments too suffer for want of teaching
faculty. But, NAAC cannot be blamed for
this situation or for commercialization of
education. NAAC is only an assessing cum
accrediting body and has no power regard-
ing the filling up of vacancies. It is the duty
of the State Governments to fill up the
vacancies, as without adequate teaching
faculty no institution can perform its role
effectively.
Apart from all this, accountability is
needed in every field of activity. Agmark,
ISI (BIS), CRISIL, ISO, FPO, etc. are there
to evaluate, standardize and accredit prod-
ucts and producers of different sorts. In
these days of globalization, it is meaning-
less to say no to accreditation of higher
educational institutions. Of course, accredi-
tation is an evolutionary process requiring
frequent revisions of evaluation methods
and monitoring mechanisms. From our ex-
perience, we feel that NAAC is moving in
the right direction.
1. Dharmapalan, B., Curr. Sci, 2005, 88, 1535.
V. RADHAKRISHNAN
V.O. Chidambaram College,
Tuticorin 628 008, India
e-mail: vrkgeologist@rediffmail.com
Can Habur Limestone curdle milk?
Rajasthan has a fascinating array of rocks
and minerals, one of which is fossil-rich
Habur limestone (also referred to as Abur
limestone1), named after the village Habur
(27°19′N : 70°33′E). This rock is consid-
ered of lower Cretaceous–Aptian age1,
which makes it 125–112 million years old2.
The brown coloured, ferruginous clay-
bearing limestone is rich in small fossils that
give it a unique, eye-catching calligraphic
texture (Figure 1). It is because of this ex-
ceptional feature that this stone finds
prideful place amongst valuable décor-
stones from Rajasthan. Narrow and small
exposures in remote desert areas add to its
Figure 1. Fossil-rich ferruginous Habur
limestone displaying unique calligraphic
texture. Sample width = 6 cm.
value because of the ‘rarity factor’. It is
erroneously believed that Emperor Akbar
obtained this stone from Arab countries to
be used in the Fatehpur Sikri Fort, because
of God’s own handwriting on it! The myth
still persists.
Recently, a sample of this limestone
was sent to us to find out what makes it
curdle milk, as reported by people in the
villages of Jaisalmer area, Rajasthan. Local
people use this stone for curdling milk in-
stead of adding curd culture. Samples of
this ‘magical stone’ are gifted to close friends
and relatives in the region! The aim of this
correspondence is to dispel any myth or
attempt to spread wrong and superstitious
information about this rock. Being fer-
ruginous and with small fossil content, the
Figure 2. SEM photomicrograph of curd-
soaked Habur limestone chip displaying
pores and micro-cavities that provide
suitable sites for curd-forming microorga-
nisms. Two white spheres (~ 3 µm each ↑)
and ‘crust’ (→) are of curds. Bar = 3 µm.
limestone contains numerous small cavities
and is more porous than other stones of
the area (Figure 2). Its unique and rare ap-
pearance adds to the legend woven around
its supposed magical properties. This stone
must have been used for curdling milk,
similar to the use of dried yeast for baking
dishes. Obtaining curd culture in the sparsely
populated desert area must have been a
problem in the region. Therefore, keeping
the culture in a suitable receptacle must
have been an ingenious solution to the
problem, which in due course of time has
become a myth. The bacteria in the pores
of the limestone are activated when the
curd-soaked limestone piece is put in warm
milk, which results in the curdling of milk.
Humans learned to make curds at least
3000 years ago3, but the earliest curd-making
method may not be to the liking of many a
reader. Curd is now made by adding com-
mon strains of bacteria to milk. Complex
protein chemistry is involved in the curdling
of milk4; in households a portion of the
previous day’s curd is used as culture.
Normally 4 to 5 h at + 40°C is needed to
form curds. Calcium ions form cross-links
between the hydrophobic portions of the
milk proteins to form larger curds5. But it
is highly unlikely that calcium from Habur
limestone has any significant role, if any,
in curd-forming. In several parts of Rajast-
han a small piece of curd-soaked muslin
cloth is used as starter culture for curdling
milk. The dry and hot climate of Rajasthan
ensures longer ‘shelf-life’ for the ingenious
curd cultures in which the fermenting

CORRESPONDENCE
CURRENT SCIENCE, VOL. 89, NO. 5, 10 SEPTEMBER 2005
730
microorganisms are activated when the cloth
or stone is put in warm milk. In case any
readers know of any other geo-myth,
please share it with others by sending it
to i2i@geologydata.info.
1. Sinha Roy, S., Mahapatra, G. and Mohanty,
M., Geology of Rajasthan, Geol. Soc. India,
Text Book Series. 1998, pp. 207–208.
2. http://www.stratigraphy.org/meso.htm, April
2005.
3. http://www.britannica.com, April 2005.
4. http://www.chem.wise.edu, April 2005.
5. http://www.itisacqui.it, April 2005.
ACKNOWLEDGEMENTS. I thank my col-
leagues Drs M. L. Nagori and S. R. Jakhar for
help with SEM studies and the Head, Depart-
ment Geology for providing facilities. I also
thank Mr G. Prabhulingaiah, Rajasthan State
Mines and Minerals Ltd, Bikaner for providing
the curd-making sample of Habur limestone.
P. S. RANAWAT
Department of Geology,
Mohanlal Sukhadia University,
Udaipur 313 001, India.
e-mail: psranawat@geolmlsu.org
Malaria millennium development goals, treatment costs and generics
Malaria is endemic in many developing
countries, particularly in the tropical and
subtropical regions. The full extent of the
epidemic cannot be measured because
many cases of malaria are not clinically di-
agnosed or reported. The World Health Or-
ganization (WHO) estimates that 300–500
million cases occur each year; this leads
to more than one million deaths1. Almost
90% of all cases occur in Sub-Saharan
Africa; children are the most affected
and malaria may account for as much as
25% of child mortality in this region.
The economic burden of epidemics such
as malaria on families and communities is
enormous. Estimates suggest that malaria
slows economic growth in Africa by
about 1.3% a year2. Goal 6 of the Mil-
lennium Development Goals emphasizes
on reducing morbidity and mortality due
to malaria, tuberculosis and HIV/AIDS2.
Accordingly, deaths due to malaria should
be halved and the year 2015 is the dead-
line for halting malaria spread. A recent
estimate revised the number of malaria
cases up to 500 million in Africa. This
clearly indicates that various programmes,
such as Roll Back Malaria initiated by
WHO, are not producing the desired re-
sults.
One of the neglected issues in the dis-
cussion on achieving the goals related to
malaria is treatment costs and the role of
generic drug manufacturers. Greenwood
et al.1 report the direct cost of malaria
treatment as US$ 2–5 per person per event.
We conducted an analysis of retail costs
of treatment of a single episode of malaria
in India using data from an Indian phar-
maceutical manufacturers’ index (Indian
Drug Review, Mediworld Publications,
New Delhi, 2005). According to this pub-
lication, the mean retail cost of various anti-
malarial drugs in Indian rupees is: chlo-
roquin 6.73, primaquin 44.24, sulphazo-
xazole–pyrimethamine 8.36, quinine
sulfate 208.32, mefloquin 219.05, pro-
guanil 157.50, artether 246.99, artesunate
246.90, artemether 223.80, and doxycycline
117.60. Recently, however, combination
therapies have been recommended for
malaria control and eradication3. These
combinations include artemesinin-based
drugs along with conventional antimalarials.
In India, retail costs of such combinations
are chloroquin–primaquin 50.97, quinine–
primaquin 252.56, sulfazoxazole–pyri-
methamine-artemisinins 247.59, quinine-
artemisinins 447.55 and mefloquinine-
artemisinins 458.28. This translates into
US$ 5–10 per person per treatment at re-
tail prices and US$ 3–7 at wholesale
prices. This amount is not different from
the older and largely ineffective non-arte-
mesin-based therapies used in Africa1.
Malaria mortality in India has fallen by
85% in the last five years, whereas the
various programmes in Africa do not re-
port any significant improvement. This
clearly implies that in the African region
people still use old medicines to counter
malaria. This may be due to the fact that
large multinational pharmaceutical com-
panies use these less developed countries
to dump their outdated drugs. On the other
hand, in India the drug policies coupled
with positive approach of pharmaceutical
industry have improved affordability and
availability of new drugs.
The World Trade Organization (WTO)
and the World Bank can also play an im-
portant role in the control of prices of
drugs. World Bank has projected an addi-
tional U$ 1 billion over a period of five
years for prevention of malaria, of which
Africa would get the largest share. While
in India, they have decided to spend a total
sum of US$ 200 million over a period of
five years for the same project. An im-
portant responsibility of WTO is in stop-
ping the malaria epidemic, but the debate
is whether or not WTO is the best place
to enforce intellectual property rights. From
an economics point of view, free trade is
good because it offers gains to all trading
partners by reducing domestic prices of
goods and services they import. Unfortu-
nately, the Trade Related aspects of Intellec-
tual Property Rights agreement cannot
guarantee such a positive outcome. Most
of the developing countries, especially
the poorest one, will not be able to use or
contribute to development of major drugs
and the costs of new pharmaceuticals are
bound to increase beyond their reach. In-
dian pharmaceutical industry can play an
important role in this scenario.
1. Greenwood, B. M., Bojang, K., Whitty, C.
J. M. and Targett, G. A. T., Lancet, 2005,
365, 1487–1498.
2. Ruxin, J., Paluzzi, J. E., Wilson, P. A., Tozan,
Y., Kruk, M. and Teklehaimanot, A., Lancet,
2005, 365, 618–621.
3. Baird, J. K., N. Engl. J. Med., 2005, 352,
1565–1577.
REVANT R. GUPTA1
RAJEEV GUPTA2,*
1Narsee Monjee College of Commerce
and Economics,
Mumbai University,
Mumbai 400 049, India
2Monilek Hospital and Research Centre,
Jawahar Nagar,
Jaipur 302 004, India
e-mail: rajeevg@satyam.net.in