1894.] MICROSCOPICAL JOURNAL. Ill 



formalin for a few hours and then cut but I failed to get 

 thin sections in this way the imbedding material being 

 too elastic to cut well. It seems necessary either to use 

 a Valentine's knife or a freezing microtome for immedi- 

 ate examination or to replace the formalin by alcohol, 

 and this by turpentine, cedar oil or chloroform and im- 

 bed in paraffine. Tissues so imbedded, cut well and the 

 formalin does not affect their staining either in mass 

 or upon the slide as regards any of the dyes that I have 

 yet tried. 



The manufacturer does not recommend the use of for- 

 malin internally, but states that the workmen exposed to 

 its vapors in the laboratory have exhibited no evidences 

 of its injurious effects. I have used alto 500 spray upon 

 my own throat without any bad effects and intend to use 

 stronger solutions to test its action. The solution used 

 had a peculiar penetrating sensation but not disagreeable. 

 Inhalation of the vapor causes a slight stinging sensa- 

 tion somewhat similar to that of ammonia and is some- 

 what irritating but seems to produce no bad effects. The 

 spray disengaged from pure formalin to disinfect some 

 plates of diphtheria that I accidentally dropped on the 

 floor and scattered over the laboratory while conducting 

 my experiments with formalin irritated my eyes some- 

 what during the exposure, but the irritation ceased im- 

 mediately after completing the disinfection leaving no 

 unpleasant consequences. 



As to the dosage in diphtheria I should expect good re- 

 sults from the application to the patches of a 1 or 2 per 

 cent solution but would not hesitate to tentatively ap- 

 ply a stronger solution if necessary to check develop- 

 ment of the bacilli. At the same time I should spray 

 the throat with a 1 to 500 solution. Clinical experience, 

 however, is necessary before formulating very definite 

 conclusions on this point. 



It is my opinion that formalin is destined to become an 



