PREFACE 



THE objects of this book are to describe in detail the 

 results obtained by a new method of experimentation 

 with individual living human cells, their importance in 

 the elucidation of the phenomena of healing, and in the 

 causation of cancer and other growths. 



The old methods of examining dead tissues and 

 cells have been useful in the past, but I venture to 

 think that those who undertake the study of living 

 human cells, and especially blood-cells, by the in-vitro 

 methods of staining, which will be hereafter described, 

 will realise that they supersede all others. This method 

 enables us to observe cells in their proper shapes, and 

 an entirely new impression is obtained concerning 

 the functions of their constituent elements and of the 

 modes by which they divide and reproduce themselves. 

 The fact that the divisions of reproduction can be 

 induced on a microscope slide by means of the natural 

 chemical agencies which cause their proliferation within 

 the body has in itself opened a fresh vista of research 

 which has not only taught us the cause of prolifera- 

 tion of ' cells in healing, but has also suggested that 

 the cause of malignancy, which appears to be re- 

 lated to that normal process, is beginning to become 

 cleared up. 



The methods which I shall describe are entirely 



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