mil] oil /Vt//s/.riil Chviimtrji (ml the hortrino. of TinniuiiUy. 2;>;> 



to 40 units of the precipitate, and the 0*4 c.c. of the imniuiie 

 serum is equivalent to 120 units of the precipitate. If, therefore, 

 P units of precipitate have been formed from a mixture of A c.c. 

 sheep's serum, i.e. 40 A equivalents, and 0*4 c.c. immune serum, 

 i.e. 120 equivalents, then there remain (40 A- P) equivalents of the 

 sheep's serum, and (120 - P) equivalents of the precipitin. If we 

 divide these quantities bj the volumes V, and form the product, as 

 in the formula above, this product ought to be a constant, according 

 to the law of Guldberff and Waage. The results are as follows : — 



In the three last experiments 1 c.c. of water was added to the 

 mixture, whereby the volume V was increased, and consequently the 

 precipitate diminished. The general agreement between the calculated 

 and the observed quantities of precipitate shows that the remaining 

 discrepancies (e.g. for A = 1"5, 2, and 15 c.c, as well as in the 

 last two figures) may be supposed to be due to the great experi- 

 mental difficulties inherent in these measurements. The constants 

 40, 120, and 250 are determined from the experiments. 



In this case we observe an increase of the precipitate P when the 

 quantity of added sheep's serum A increases. But a maximum is 

 soon found, when A = 3 c.c, and thereafter the precipitate decreases. 

 The calculation indicates that this circumstance is only due to the 

 increase in volume, that is, to the attenuation, whereby the concentra- 

 tion of the immune serum diminishes without a commensurate increase 

 in the concentration of the sheep's serum. 



But, as stated above, cases are not rare in which a real chemical 



