928 THE AMERICAN NATURALIST. | [Vor. XXXV. 
the animal had been immunified. These results have been 
confirmed by Wassermann and Schütze, and demonstrate that 
there are essential differences in the composition of the albu- 
minous molecule in the milks of man, cattle, and goat. 
Myers demonstrated the existence of precipitins in the blood 
of animals treated with peptone, the precipitins acting only 
upon peptone. 
The credit of having discovered the existence of specific 
precipitins in the bodies of animals treated with blood belongs 
to Tchistovitch. He inoculated animals with eel serum, which 
is toxic, and noticed that an anti-toxin made its appearance in 
the serum of the treated animals, but in addition their serum 
acquired the property of producing a precipitation when added 
to eel serum, whereas it did not act on other sera. A specific 
anti-body was also produced in rabbits treated with horse 
serum. Bordet demonstrated the existence of specific pre- 
cipitins in rabbits which had been treated with fowl's blood. 
The anti-serum of these rabbits also produced a slight reaction 
in pigeon blood, showing that the bloods of the fowl and. 
pigeon are of a somewhat similar composition. Nolf separated 
the corpuscles from the serum and treated two sets of animals 
with the separated blood ingredients. He found that only 
the serum-treated animals yielded the specific precipitin. He 
treated the serum with magnesium sulphate, thus removing the 
globulin. Animals were treated with globulin and albumin 
solutions derived from the serum, and it was found that pre- 
cipitins were formed only in the serum of animals treated with 
globulin solutions. 
Myers treated rabbits with fowl's egg albumin, as also with 
serum globulin of the sheep and bullock. He also observed 
the formation of specific precipitins in the serum of the treated 
animals, although a slight reaction took place on adding the 
anti-serum for sheep globulin to that for ox globulin and vice 
versa. Uhlenhuth also treated rabbits with egg albumin, and 
found that the anti-cserum gave a reaction with I: 100,000 
dilutions of egg albumin, whereas the most delicate chemical 
tests only gave a reaction with dilutions of I : 1000. He made 
the interesting observations that the precipitin appeared in the 
