It was found in another series of experiments[58] that the haemoglobinuria caused by saponin and by quillain, which is a dried extract of Quillaja bark, may be inhibited by calcium chloride. The intravenous injection of 2 c.c. ¹⁄₄% quillain always produced haemoglobinuria in a rabbit weighing about 1,200 g. If the dilution of the quillain were made with m/6 CaCl_{2} instead of water, _e.g._, 2 c.c. 1% quillain + 6 c.c. m/6 CaCl_{2} and 2 c.c. of this injected intravenously, no haemoglobinuria resulted, although the concentration of the quillain was the same in both cases. The CaCl_{2} does not stop the excretion of the haemoglobin by the kidneys, for if the saponin or quillain be given first and the haemoglobinuria established, the subsequent injection of CaCl_{2} does not stop the excretion of haemoglobin. This is explained by a large number of experiments in which it was shown that the haemolysis caused by saponin, quillain, or digitalin is particularly inhibited by calcium chloride and magnesium chloride. This can be seen in the following table in which defibrinated rabbit’s blood is used, and the effects of CaCl_{2} and MgCl_{2} are compared with that of NaCl. 1 c.c. blood 1 c.c. blood 1 c.c. blood Time 5 c.c. m/6 NaCl 5 c.c. m/6 MgCl_{2} 5 c.c. m/6 CaCl_{2} 3 drops 0.5% saponin 3 drops 0.5% saponin 3 drops 0.5% saponin A.M. 10:22 10:24 change of color no change no change 10:27 almost transparent no change no change 10:30 laking almost complete no change no change 10:45 laking complete no change no change P.M. 1:00 laking complete corpuscles settled same as MgCl_{2} to bottom; supernatant mixture fluid colored; mixture quite opaque on shaking It is of considerable interest to note that these substances, saponin, quillain, and digitalin, act not only as haemolytics, but also as diuretics. This was shown in a number of experiments.[59] As shown in the following table, the injection of a very small quantity of saponin produces a distinct increase in the quantity of urine excreted.