THERE is an interesting story regarding the discovery of magnet in the West although the East knew of it far in advance. It is said that centuries before Christ a shepherd boy named Magnes was once roaming about on the Mount Ida in Greece.
Suddenly his iron-capped stick stuck to a boulder and when the astounded boy was using all his might to snatch his staff free from the grip of the mysterious stone, his iron-stacked shoes got stuck to it and he fell flat. Magnet was discovered and it was named after the shepherd boy Magnes.
Just as Earth’s magnetic field preserves life, magnetotherapy preserves health and prevents diseases.
-CHRISTOPHER HILLS
It is also said that magnet was first discovered and found in abundance in Magnesia in Asia Minor and named Magnetite
Magnet has been given different names in different countries. The Greek called it ‘Magnetis’ or ‘Mag- nesetos’. The English recognised it by the name of ‘Lodestone’ or ‘Loadstone’ (directing stone). In France it is ‘Aimant’ (loving magnet).
In India we have named it ‘Chumbak’ (the kissing stone). In Arabic it has become Maqnatees’, apparently a distortion of the word Mag- net. The Chinese call it ‘Chu She’ (loving stone).
All these names point to the attractional and directional properties of magnet known to the ancient people and exploited by them in making health-giving mystery rings on the one hand and mariner’s compasses on the
other.
The magnetic stone found in nature is chiefly com- posed of iron and oxygen in the form of oxide having molecular formulae Fe3O4.
Although this stone is abundantly found but this natural magnet failed to meet the growing demand of developing science and technology, because it could not be given the required numerous shapes and could not be had in varying strengths. Therefore, man started making artificial magnets and today natural magnets are rarely seen.
Magnets are artificially made in three ways. A mag- net is rubbed on the magnetic material in unidirectional manner. As a result of this repeated rubbing, the subject material is magnetised but its power remains weak
For a stronger magnetic force, electrical method of magneti- sation has been in use. An insulated wire is wound round the magnetic material and direct current passed through the coil.
This flowing electric current renders the material magnetic and the varying periods of expo- sure give it varying strengths.
In recent times scientists have devised a machine called Magnetiser which charges the magnetic material instantaneously without use of any wires. This is the third and most up-to-date method.
Molecular Theory
Here a question arises. What change occurs in a magnetic material when it shifts from its non-magneti- sed state to the magnetised one. The answer is provided by the molecular theory of magnetism. As has been mentioned, all the molecules constituting a magnetic material are in reality nothing but tiny magnets.
In the non-magnetised material, these molecules lie misaligned, i.e:, similar poles of molecules do not point to the same direction. They lie jumbled up, north pole neutralising the south pole and vice versa.
The process of magneti- sation changes the existing position and makes north poles of molecules turn to one end and south poles to the other end, this is called the right alignment of mole- cules.
But any extent of magnetisation fails to put all the molecules of a piece in the right alignment and the percentage of aligned molecules in a piece fixes the power of its magnetism. Moreover, the concentration of aligned molecules is always equally maximum at the two ends, called poles and minimum at the mid line.
The molecular theory of magnetism also answers a connected question which naturally issues and fills us with curiosity. Why a magnet attracts a non-magneti- sed piece of iron or other magnetic materials? We know that each pole of a magnet attracts the opposite poles of another magnet.
Any non-magnetic material remains non-magnetised because its molecular constituents (themselves tiny magnets) lie misaligned and jumbled up. Their similar poles do not remain in the same direction.
When any pole of a magnet is applied to a piece of iron, this pole is confronted with the opposite poles of a number of molecules in the material. The material is thus instantaneously attracted towards the magnet.
Two Types of Magnet
Artificial magnets are of two types: permanent mag- nets and electro-magnets. Permanent magnets remain magnetised permanently, once they have been fully charged with electric current. They are used in radio speakers, telephones, galvanometers and innumerable other appliances.
Electro-magnets work only when they are connected with electricity and such magnets are switched on and off with the switching on and off of the electric current. They are used in electric door bells, telegraphic machines, electric cranes, etc. The healing purpose of magnetotherapy is best served by permanent magnets, as electromagnets essentially suffer from fluctuations.
Permanent Magnets
Permanent magnets are made from a wide range of materials, iron being the main. But commonly an alloy called Alnico composed of aluminium, nickel, iron and cobalt in differing proportions, is used for making per- manent magnets.
In addition, some magnets are made from a synthetic material prepared from oxides of ferric and barium and are called ceramic, ferrite or graphite magnets or simply ceramic magnets.
Magnets from both these materials are made in a number of shapes and sizes as needed. Some of them are bar shaped, some are cylindrical, some cylindrical and with or without holes, some are ring-shaped, or rectangular, with holes or without holes, some are crescent like or U-shaped or horse-shoe-shaped, squares with holes or without holes, etc. etc.
In Magnetic treatment, cylindrical shaped magnets of Alnico and crescent shaped magnets of ceramic material mostly are used.
Unique Properties
The phenomenon of magnetism has several peculiar features which seek our indulgence before we go ahead with our subject, the therapeutic exploitation of mag- nets. These are as under:
Every magnet, big or small, even the tiniest, must have two poles–north pole and south pole-just like the two poles of the earth. Weber, a physicist, has establi- shed that molecules of a magnetic material are the tiniest magnets and inspite of their atomic size possess both the poles.
If a bar magnet is cut or broken into two or a number of pieces, each piece will immediately become an independent magnet with both the poles at both ends. Thus, out of one magnet innumerable magnets can be made and although power of each piece will not be the same as that of the whole, the magnetism will remain preserved to the molecule.
Poles are actu- ally concentrations of magnetism at the two ends of a magnet. The power of magnetism in a magnet is at its highest at its two poles but lowest at the midline equi- distant from the two poles.
If a bar magnet is dropped on a heap of pins, the maximum number of pins will be found stuck to the two poles but minimum to the middle.
This is why in magnetotherapy single poles are used and those also of cylindrical shaped encased mag- nets which have the broadest magnetised surface.
- Another important feature of magnetism is that opposite poles attract each other but like poles repel. If north and south poles of two magnets are confronted with each other, they will be found clamouring for a union but if the same poles are brought together they will run away from each other. This fact is almost com- mon knowledge but it has an implication important for magnetotherapy. The fact of attraction and repulsion proves that the two poles of a magnet differ in nature and consequently in therapeutic effect also. It has al- ready been mentioned that Dr. Hahnemann prepared two separate homoeopathic medicines from the two poles. The whole structure of treatment in mågneto- therapy has been raised on this polarity in the nature and properties of the two poles which will be dealt with in another chapter.
- The third feature concerns the concept of mag- netic lines of force. The region covered by the lines of force around the magnet is called its magnetic field.
to - The strength of a magnetic field is subject the strength of the magnet, but irrespective of the strength of the magnet the expanse of the magnetic field is always infinite, just like the bigger and bigger rings created by sound in space. The grip of magnetic field continuously weakens with the distance from the magnet but it never ends or becomes non-existent. This magnetic field is the medium or agent exploited in magnetotherapy for therapeutic purposes.
Measurement of Strength
The strength of a magnet or its magnetic field is measured by an instrument called magnetometer or gaussmeter in gauss units or oersted. As this instrument is generally available only in laboratories, the strength of a magnet is commonly measured in terms of the iron- weight it can lift.
A magnet which can lift 2 lbs. of it is of about 500—600 gauss power. The other with lifting capacity of 5 lbs. will be 900 to 1,250 gauss, of 25 lbs. close to 2,500 gauss and 50 lbs will be between 3,500 and 4,500 gauss.
In magnet-treatment, magnets of 1,500 to 3,000 gauss power are applied to big muscles or to strong parts of body e.g. hands, back, hips, knees, legs, feet, etc., and also in cases of chronic diseases like rheumatism, but magnets of about 500 gauss power only are applied to delicate parts like eyes, temples, nose, throat, etc. In cases of small children and infants also only these weak magnets are used.
Marking of Poles
It has been stated above that both the poles of a magnet differ in nature and possess differing therapeutic properties. Hence, marking of poles is of basic impor- tance for magnetotherapy.
We all know about earth’s geographical poles. The earth also has its magnetic north and south poles. It has been found that earth’s magnetic poles do not coincide with its geographical poles.
On the contrary, earth’s magnetic north pole is somewhere near its geographical south pole and its magnetic south pole is in the neigh- bourhood of its geographical north pole.
Traditionally the end of the magnetic needle of the compass pointing towards geographical north is marked as north pole of the magnetic needle.
This is because north pole of a magnet will naturally be attracted towards the magnetic south pole of earth situated in the north and vice versa. The poles of magnets used in magnetotherapy the world over are marked according to this principle.
However, some researchers in U.S.A. have contradicted this traditional system of the marking of poles and have reversed it.
According to the theory advanced by them the traditional north pole of a magnet becomes south pole and the south pole becomes north pole.
Although these researchers have not yet been able to convince any autho- rities in the world of science and they are in a microscopic minority, some magnetotherapists the world over, including some in India, have subscribed to this view and have reversed the marking of poles on the magnets used by them or recommended by them to the lay users.
(Accord- ing to a PTI News dated November 18, 1983 published in the Hindustan Times two scientists at the National Geo- physical Research Institute (NGRI), Hyderabad claim to have discovered for the first time a remarkable periodicity in the geomagnetic reversals of the earth’s magnetic field). This has created some confusion and problems, specially for the non-technical users.
Hence a few words are necessary to clear the mist.
Since the time when the first compass was brought into being till this day when the magnet is being put to the most diverse and complex technical uses the scientists, technicians and manufacturers of magnets have followed the universally accepted traditional method of the marking of the poles.
All scientific books throughout the world and all the encyclo- paedia carry this very view.
