1894.] MICROSCOPICAL JOURNAL. 105 



Early in October the American agents, (Schering and 

 Grlatz, of New York), kindly sent me a small vial of for- 

 malin, since when I have been testing it in various ways 

 in the bacteriological laboratory at Howard University 

 and have undertaken some experiments with it upon the 

 bacillus of diphtheria. These have not as yet been com- 

 pleted; but so far as they have been carried are eminently 

 satisfactory and seem to show that in formic aldehyde 

 we have an agent which is superior in its germicidal 

 action to corrosive sublimate in solutions of a strength 

 which can be well tolerated and which so far as I can 

 determine is not injurious. I have not yet had an oppor- 

 tunity to test it clinically in cases of diphtheria ; but if 

 my expectations are realized it will prove to be a great 

 boom to humanity, and it is with the hope that some of 

 my hearers will test it in the sick room that these pre- 

 liminary experiments are now brought to the attention 

 of the society. 



Diphtheria is now known to be primarily a local dis- 

 ease. The bacillus which stands in an etiological rela- 

 tion to it develops at the point of inoculation, usually the 

 mucous membrane of the throat, and does Eot invade the 

 blood or organs unless it be under very exceptional cir- 

 cumstances, the secondary or constitutional symptoms 

 being due to the absorption of soluble toxalbumins pro- 

 duced by the bacilli and not to the presence of the germs 

 themselves. It is manifest, therefore, that if we can de- 

 stroy the germs or inhibit their development in ^/^6' early 

 stage of the disease, before sufficient of the toxalbumin 

 has been produced and absorbed to destroy the patient, 

 we shall be able to avert a fatal termination and to rob 

 this justly much dreaded disease of its chief terrors. 



This statement is by no means based wholly upon the- 

 oretical considerations for it has been proved by care- 

 fully conducted investigations that in cases treated 

 locally by germicides the bacilli disappear from the throat 



