CHANCE 



Hospital a physiologist was surprised and puzzled to find his 

 frogs' hearts continued to beat for many hours. The only possible 

 explanation he could think of was that it was a seasonal effect 

 and this he actually suggested in a report. Then it was found 

 that the explanation was that his laboratory assistant had used 

 tap water instead of distilled water to make up the saline solution. 

 With this clue it was easy to determine what salts in the tap 

 water were responsible for the increased physiological activity. 

 This was what led Sidney Ringer to develop the solution which 

 bears his name and which has contributed so much to experi- 

 mental physiology. ^^ 



Dr. H. E. Durham has left the following written account of 

 the discovery of agglutination of bacteria by antiserum. 



"It was a memorable morning in November 1894, when we 

 had all made ready with culture and serum provided by Pfeiffer 

 to test his diagnostic reaction in vivo. Professor Gruber called out 

 to me ' Durham ! Kommen Sie her, schauen Sie an ! ' Before 

 making our first injection with the mixtures of serum and vibrios, 

 he had put a specimen under the microscope and there agglutina- 

 tion was displayed. A few days later, we had been making our 

 mixtures in small sterilised glass pots, it happened that none 

 were ready sterilised, so I had to make use of sterile test-tubes; 

 those containing the mixture of culture and serum were left 

 standing for a short time and then I called, ' Herr Professor ! 

 Kommen Sie her, schauen Sie an! ' the phenomenon of sedi- 

 mentation was before his eyes! Thus there were two techniques 

 available, the microscopic and the macroscopic." 



The discovery was quite unexpected and not anticipated by any 

 hypothesis. It occurred incidentally in the course of another 

 investigation, and macroscopic agglutination was found owing 

 to the fortuitous lack of sterilised glass pots. [I am indebted to 

 Professor H. R. Dean for showing me Durham's manuscript.] 

 Gowland Hopkins, whom many consider the father of bio- 

 chemistry, gave his practical class a certain well-known test for 

 proteins to carry out as an exercise, but all the students failed to 

 elicit the reaction. Investigation revealed that the reaction was 

 only obtained when the acetic acid employed contained an 

 impurity, glyoxylic acid, which thereafter became the standard 

 test reagent. Hopkins followed up this clue further and sought 



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