The reader might wonder why a work setting out to 
discuss the latest developments in nuclear physics 
should be called Matter and Antimatter. 
The reason 
is that the recent discovery of anti-protons and 
anti-neutrons, completing the list of antiparticles, 
has led physicists to coin the word 'antimatter . We 
shall be careful in our use of this word, if only to 
bring it down from the fantastic heights to which 
the. popular press has elevated it. 
On the whole, attempts at popularisation are 
laudable enough, but when it comes to modern 
physics they are fraught with danger. Here reality 
is often represented by mathematical 
equations 
beyond the reader's grasp, a fact which encourages 
many a sensationalist writer to indulge in fantasies. 
The current interest in anti-particles is by no means 
due to their novelty—their existence was predicted 
in a theoretical paper published as long ago as March 
1930, and the first anti-particle (the positive electron) 
was observed and identified in 1933. At the time the 
news caused no stir outside the very narrow circle 
of specialists. 
Nowadays, the moment a new particle is identified, 
it is announced to the public, and despite the reserve 
of physicists, the popular press has no hesitation in 
pontificating about its unknown properties. 
Though not brand-new, therefore, the problem of 
anti-particles is nevertheless of great interest, no only because of the old questions it resolves but also 
because of the new questions it poses. 
The discovery of anti-protons and anti-neutrons 
has confirmed the general validity of the theory, 
presented by Dirac, a young English mathematician, 
to the Royal Society on the 6th December, 1929. 
Do anti-particles have the property of combining 
to form a negative anti-nucleus which, together with 
positive electrons would make up an anti-atom? Is 
this how we must conceive the structure of so-called 
antimatter? 
Inasmuch as so small a book can do justice to the 
labours of some of the greatest scientists of the past 
thirty years, I shall try to show what discoveries have 
led physicists to ask these and similar questions.

No ISBN
127 pages