It has been found that blood can be transmitted only between animals that are closely related. The degree of relationship between these animals is determined by what is known as the serological evidence. There are various methods of doing so; the method employed by George Nuttall is called the precipitation method.
It has been discovered that blood can only be transferred between animals with close familial ties. This connection is measured using serological evidence, and there are various techniques for doing so. George Nuttall's approach, called the precipitation method, is one such technique.