Abstract
1) Tyrosine and cystine, two of the amino-acids which control the respiration of Escherich's bacilli, were used in this experiment. Both of these two acids could promote the production of agglutinin for typhoid bacilli to some extent, and at the same time, they were able to prolong the duration of the agglutinin maintained in the blood.
2) Valine and proline employed in this experiment, the other two of the aminoacids that promote the respiration of Escherich's bacilli, acted inhibitory to some extent upon the production of the agglutinin for typhoid bacilli or had no effect on it but, as to the duration of the agglutinin maintained in the blood, they were superior to the control, though they were inferior to the former two acids.
