1905.] Crystalloids and Colloids through Gelatine. 315 



in a previous communication,* it was found that the filtrates from 

 megatherium lysin were strongly hemolytic, and it was necessary to 

 determine if this haemolysis was due in any degree to change in the 

 concentration of sodium chloride. 



Method. — The filters used contained 9 per cent, gelatine in 08 per cent. 

 NaCl, and about 50 c.c. of 08 per cent. NaCl were pressed through at 

 100 atmospheres and 10° to 12° C, the filtrates being collected in fractions 

 of about 4 c.c. The NaCl content of 1 c.c. of the fractions of filtrate, the 

 residual liquid left in the filter case and the original fluid, was determined 

 by titration with 1/100 normal silver nitrate, using potassium chromate as 

 an indicator. The hemolytic powers of the same fluids were determined 

 in these and all other experiments in this paper, unless otherwise stated, 

 by mixing 1 c.c. of the respective fractions with 2 c.c. of 2"5 per cent, 

 guinea-pig's red corpuscles which had been washed and suspended in 

 - 8 per cent. NaCl. The mixtures were heated to 37° C. for three hours, 

 well shaken every 30 minutes, and allowed to sediment generally about 

 12 hours in the ice chest at 6° to 8° C. 



The intensity of tint of the supernatant fluid was then determined by 

 comparison with the scale of a von Fleischl haemoglobinometer which had 

 been standardised by a blood solution of known content. Complete 

 haemolysis is indicated by the index (100). 



Examination for Sodium Chloride and Hccmolytic Power. — Experiment 

 No. 2, Table I, represents one out of four similar experiments. 



Original Fluid: 0'81 per cent. NaCl given in the table as Orig. (100). 



Filtrates : The relative concentrations of the 1st, 4th, and 14th fractions 

 were (474), (89-5), and (99-2) respectively. 



Eesidual Fluid : When tested immediately after decompression had the 

 value (100) exactly, but, on allowing to stand 12 hours in the filter case, 

 showed the relative concentration (105). 



Haemolytic Powers : No haemolysis was obtained under the standard 

 conditions with either filtrates, residual fluid, or the original saline. 



Conclusions. — The typical crystalloid, sodium chloride, is markedly 

 retained on filtration through gelatine which originally contained the same 

 concentration of saline as the fluid filtered. The salt taken up by the 

 gelatine is expressed or diffuses into the residual fluid after decompression. 

 The diminution in salt concentration in the filtrate is insufficient to cause 

 haemolysis under the standard conditions. 



* Loc. cit. 



