310 INFECTION AND RESISTANCE 



erties of the leukocyte extracts are attributable, in part at least, to 

 their positively chemotactic effect. 



The entire problem opened up by the work of Hiss cannot be 

 regarded as settled. Observations, both experimental and clinical, 

 are still in progress, and it is hoped that the next few years may 

 definitely decide in how far this treatment is applicable to human 

 cases. It is not easy to draw conclusions from clinical observations 

 since it is impossible to parallel such cases with untreated controls; 

 in consequence the truth can be elucidated only by a multiplication of 

 statistics. While the writer and others have treated a great many 

 cases with disappointment, again the striking results occasionally 

 observed have been so encouraging that it seems of the utmost im- 

 portance to give the treatment extensive trial, especially since many 

 injections have been made without any harm whatever to the patients. 

 Although the experience thus far gathered permits of no definite 

 conclusions, the writer would suggest from his own experience and 

 his observation of that of others that the use of the leukocyte extract 

 of Hiss be confined for the present to diseases like erysipelas, menin- 

 gitis, and the pyogenic infections in which the process is distinctly 

 localized and no general septicemia has supervened. It should also 

 be given a thorough trial in broncho- and lobar pneumonia in which 

 the bacteriemia which occurs represents very probably a constant dis- 

 charge into the blood stream of bacteria from the pneumonic focus, 

 rather than the firm establishment of bacterial growth within the 

 blood itself. With few exceptions absolutely no results seem to have 

 followed its use when such a septicemia has become established. In 

 the class of cases first mentioned, however, where a localized infec- 

 tion has been obst'inate and unusually violent, many brilliant results 

 have been obtained. Judging from the results of Dr. Adrian Lam- 

 bert, and more recent ones obtained by Dr. Dwyer, we would have no 

 hesitation in stating that erysipelas is favorably influenced in most 

 cases. The above suggestions are made since it seems that in the 

 question of clinical therapy much delay in the proper estimation of 

 the value of a new type of treatment can be avoided by an intelligent 

 choice of cases. 



