PROCEEDINGS OF THE SOCIETY. ' 93 



these spheres of activity, he felt naturally interested in the subject of 

 the evening- lecture. He was well aware of the existence of M. Goby's 

 work on similar lines to those described by Mr. Barnard, and it had been 

 his privilege to criticize it, so that he was well versed in what had been 

 seen in London of the radiography of Foraminifera sent over from 

 Paris. The use of the X-rays in connexion with the Microscope had re- 

 solved itself in his experience into two directions. Firstly, the Micro- 

 scope representation of the effect produced by the cathode rays on the 

 metallic disk known as the anticathode, taken from an old tube which 

 had done its work. If such an anticathode were examined by a Micro- 

 scope objective, very graphic evidence would be found of the results by 

 the ionic impact which had taken place upon the anticathode. Another 

 and more serious matter, however, such as might arise from the practice 

 of X-ray microscopy, was the appearance of certain diseases, known a& 

 X-ray dermatitis, produced by too frequent and incautious exposure 

 to X-rays. A year or so ago the Rontgen Society had a visit from a 

 French surgeon, Dr. Cluny, who produced a very fine collection of 

 photomicrographs in colour of cancerous growths following on the 

 obstinative inflammation of the skin brought about by exposure to 

 X-rays. A hard tube might be used with comparative safety, but this 

 particular soft form of tube required for the work to which Mr. Barnard 

 had been directing then attention was extremely dangerous to use, 

 and he thought he would be wrong if he did not outline the risk run in 

 employing such a tube. One suggestion he would like to make was, 

 that in his work with the X-rays in connexion with the microscopic 

 examination of molluscan shells, he had found it more satisfactory to- 

 carry the photography one stage further, and produce negative rather 

 than positive results — and he threw out the hint to Mr. Barnard in this 

 respect. He would like to ask Mr. Barnard on what he based his ex- 

 posure, whether he judged it by the penetration of the tube, or was it a 

 question of the distance of the object from the anticathode ? The 

 weight and density of the specimen examined also entered largely into 

 the calculation. 



Dr. Geo. H. Rodman, in speaking of the granularity complained of 

 by Mr. Barnard, said that from experience of many forms of X-ray 

 plates he thought that the lecturer would not suffer in this respect if he 

 used a plate suggested by Dr. Mees and designed by him for special 

 X-ray investigation. In his (the speaker's) hands, and with careful 

 development, this plate left little to be desired. He wished to con- 

 gratulate the Society upon Mr. Barnard's most excellent paper and 

 demonstration ; the resnlts shown upon the screen had been highly 

 satisfactory, and he thought they exceeded in beauty, and certainly in 

 descriptive value, those first of all shown in this country by Monsieur 

 Goby in 1913. 



Mr. Barnard expressed his thanks to Mr. Heron- Allen for his 

 extremely laudatory remarks which he felt he really did not deserve. 

 He quite thought with him that at least a light was shed upon what up 

 to then had been impenetrable gloom. He did not think that anything 

 he had said inferred more than that. The particular way in which 

 X-ravs could be utilized to their fullest advantage in microscopy 



