A STUDY OF THE COMBINED ACTION OF X-RAYS 

 AND OF VITAL STAINS UPON PARAMCECIA. 



W. M. BALDWIN, 

 UNION UNIVERSITY (ALBANY) MEDICAL COLLEGE. 



It has been definitely recognized that X-rays exercise injurious 

 effects upon both vegetable and animal forms of life and, more- 

 over, that the adult tissues possess a variable absorption capacity 

 for this form of energy. On the other hand, experiments con- 

 ducted for the purpose of ascertaining the nature of the reactions 

 of bacteria to X-rays have generally proved negative. In 

 marked contrast to seeming bacterial immunity, unicellular 

 organisms show a marked degree of susceptibility. 



During the spring and summer of 1916, through the courtesy 

 of the Research Laboratory of the General Electric Company 

 at Schenectady, the author was enabled to make use of X-ray 

 energy in a prosecution of the study of the action of vital stains 

 upon various forms of animal life. These experiments were 

 begun with paramoecia. The investigation comprised, first, the 

 study of the action of vital stains upon these forms of life; 

 secondly, of the effect of X-rays acting alone; and lastly, a study 

 of the reaction to X-ray energy while under the influence of these 

 vital stains. The stains used for this purpose were Nilblau 

 sulfat (Gruebler), Alizarinblau (S), Trypanblau, Isaminblau, 

 Nilblau chlorhydrat, Trypanrot, Dahlia (Gruebler), Neutral red, 

 Anilin red (Sudan III. oil), Janus green (Eimer and Amend), 

 Methylene blue (B.X.) (Merck). These stains were in the form 

 of dry powders. Solutions were prepared with tap water. It 

 had been previously ascertained that this tap water contained 

 no substances injurious to the organisms either at the time of 

 raying or thereafter. The solutions of the stains were freshly 

 prepared for each experiment. In the majority of instances a 

 stock solution consisting of o.ooi gm. of stain to 200 c.c. of water 

 was used, a subsequent dilution of this stain being made before 

 each experiment. This stock solution was not kept for a period 



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