MR. CROOKED EXPERIMENTS. 267 



and its effect upon the olfactory nerves of some per- 

 sons is almost pleasant. To the efficacy of carbolic 

 acid, numerous facts advanced in the following pages, 

 abundantly testify. For much of what is known con- 

 cerning the action of carbolic acid, we are indebted to 

 Mr. Crookes, who has performed a great number of 

 most careful experiments, by which it appears to me 

 the usefulness of this disinfectant is established. In 

 order that the reader may form a general notion of 

 the nature of the evidence upon which this conclusion 

 is based, I propose to give a short account of 

 Mr. Crookes' researches, and the results he has 

 arrived at. 



In his report to Her Majesty's Commissioners, in 

 1866, Mr. Crookes has drawn conclusions concerning 

 the nature of the poison of cattle plague, almost identi- 

 cal with my own detailed in this work. This agreement 

 is remarkable, inasmuch as two very different methods 

 of investigation have been pursued by us, and quite 

 independently. The two reports were presented at 

 the same time, and neither observer was aware of the 

 results arrived at by the other. In this case chemical 

 investigation and microscopic observation have led to 

 the adoption of similar inferences, and the establish- 

 ment of the same kind of theory concerning the 

 nature and action of contagious poisons. 



