Тик scientific study of the structure of аlloys was first developed by the physical chemist and the metallurgist. It is now (ending to become the province of the physicist and mathematician. The student who is interested in this important subject is often inclined to feel that, until he has specialised in all tbк will help to indicate lo the nut. of necessity, specialist render to the man engaged in industry and to the student at the laboratory bench -the main directions along which progress has been, ami indeed is Wing. made, lie feels that his work in writing the hook will Ik- well repaid if he has succeeded in presenting his subject matter in such я way thut it will be of direct use to practising and student metallurgists, and to similar groups of chemists and physicists, who are now becoming increasingly concerned with inetnls and alloys. He would her.- point out thai it is only in the manner and order of the presentation of his subject that he would lay any claim to originality of treatment. The author hopes that this little book will help, if only in a small way. to convey to students of Metallurgy. Chemistry and Physics a broad outline of the contributions made within recent ума by their predecessors towards the solving of what were some of the bewildering problems of the science of alloys.