PREFACE XV11 



enabled to obtain the assistance of Dr. Cropper. In 

 October, 1909, I happened to be discussing with Mr. 

 Sharpies, an energetic supporter of these researches, 

 the difficulty of my finding time to undertake the 

 investigation of some of the by.-issues revealed by the 

 new method issues which might prove to be of 

 importance. Our conversation was overheard by a 

 gentleman, who I afterwards ascertained was Mr. 

 J. H. McFadden, of Philadelphia, whose acquaintance 

 I had only just made, and to whom I was practically 

 a stranger. Mr. McFadden immediately became in- 

 terested, and placed a large sum of money at my 

 disposal in order that I might obtain other assistance 

 to further these researches for a period of two years. 

 In March, 1910, Mr. McFadden further instructed me 

 to the effect that if I conscientiously thought that 

 further funds could usefully be spent in the advance- 

 ment of these researches I was to incur that expendi- 

 ture. In fact, he has not only supplied me with the 

 assistance of Dr. Cropper, but he has also been the 

 means of equipping a laboratory for him, kindly lent 

 by the Liverpool School of Tropical Medicine, but 

 also in defraying the serious expenditure connected 

 with the manufacture of the substance we call "globin" 

 from crystalline haemoglobin. Mr. McFadden has also 

 enabled me to take the large number of photomicro- 

 graphs which record the phenomena seen under the 

 microscope; ajnd, lastly, he has borne the entire cost 

 of the publication of this volume and the reproduction 

 of the photomicrographs which illustrate it. 



I fear that I shall never be able to thank Mr. 



