In a previous article from this laboratory (1), it was pointed out that a rabbit, sensitized to some protein, will show the presence of of both skin sensitivity and serum precipitins for some weeks after it enters the sensitized state; that with time, the serum precipitins disappear from the circulation, while the capacity of the animals to give a skin sensitivity response remains. In this article data will be presented which demonstrate the relation between skin sensitivity and serum precipitins on a more quantitative basis.
Experimental. Preliminary experiments have shown that the greater the quantity of protein used in the sensitization of a rabbit, within certain limits, the more extensive is the production of serum precipitins by the animal. On the basis of this observation, a series of rabbits was sensitized with small amounts of protein, with a view to limiting the production of serum precipitins. It was recognized that the skin sensitivity response would also be limited.