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Scientific Proceedings (66). 



globin with any certainty. The guaiac test is sometimes faintly 

 positive after the first twenty-four hours but so it sometimes is in 

 control rabbits bled and injected with Ringer's solution, and at 

 times even in normal rabbits. There is no rise in temperature 

 and immediately after the operation the transfused animals are 

 lively and seem quite normal. Control rabbits in which the 

 blood is replaced by Ringer's solution recover very slowly from the 

 profound anaemia. Animals of which the blood is replaced by 

 blood collected and kept in Ringer's citrate may show severe dis- 

 turbance associated with hemoglobin in the urine. And an animal 

 transfused with blood kept in Ringer's solution had intense 

 hemoglobinuria and died in convulsions. There is no doubt 

 that washed erythrocytes left in a sugar-Ringer's mixture are 

 really preserved alive, and preserved better than in plain Ringer's 

 or in plasma-Ringer's-citrate. 1 



Weil has kept guinea-pig blood and dog blood several days in 

 plasma with a minimum of citrate and then revived exsanguinated 

 animals with it. 2 Do red cells survive longer in the preservative 

 solutions we have devised than in such plasma citrate? There is 

 no doubt that human cells and sheep cells do. In plasma-citrate 

 these rapidly disintegrate. Rabbit's cells last longer but in their 

 case we have had better results with the preservatives than with a 

 plasma-Ringer's-citrate. On the other hand, it is possible that 

 an optimum plasma-citrate medium has not yet been found. 

 Our most recent experiments demonstrate that the blood of some 

 species when allowed to flow directly into a large excess of a 

 preservative fluid in which citrate is present can be kept for long 

 periods. And since the cells soon settle out, and practically all 

 the preserving fluid can be pipetted off previous to the employment 

 of the blood for injection this constitutes a great simplification 

 of method. 



1 Locke used one tenth of one per cent, of dextrose in the solution which bears 

 his name. This amount of sugar is far too little for any preservative effect on the 

 red blood cell. 



2 R. Weil, Jour. Am. Med. Assn., 1915, LXIV, 425. 



