EXAMINATION OF HYDROGEN DIOXID SOLUTIONS. 15 



We can account for this by your not using a desiccator, for if it is dried any other way 

 it will take moisture from llm air, thereby greatly increasing the residue. 



We have never put out any peroxid which runs higher in residue than the U. 8. P. 

 allows. 



Comment by authors. All moisture determinations were made by 

 cooling the dried material in a desiccator. 



THE DREVET MANUFACTURING Co. 



* * * We note the analyses of our various preparations made by your depart- 

 ment, and are absolutely at a loss to understand the results obtained, unless perhaps 

 the samples used were very old. 



As you probably know, we were about the first to manufacture the medicinal 

 peroxid of hydrogen, and we have jealously guarded the high standard of our prepara- 

 tions for more than 30 years and beg of you the privilege of submitting for your careful 

 examination samples of our preparations taken from our present stock on hand, and 

 at the same time we would kindly ask you to allow us to offer certificates of analyses 

 made by well-known and prominent chemists of this city for your consideration. 



We would be pleased to have your representative call and collect personally these 

 samples from our stock if you wish, or we would be glad to forward such samples to 

 you. 



Trusting you will grant our request, and assuring you of our earnest desire and efforts 

 to place our goods on the market in full conformity with or even superior to the 

 U. S. P. standard, we beg to remain. 



HANCE BROTHERS & WHITE. 



We received yours of the 16th ultimo on the 28th. At the same date we inclosed 

 it to Mr. John Bene, Brooklyn, N. Y., from whom we procure our supply of peroxid 

 hydrogen. We have examined the articles several times and found it to comply so 

 closely with the U. S. P. requirements, and in view of its perishable nature and its 

 use almost entirely for external purposes, have issued it as being equal to other makes. 



We are herewith inclosing Mr. Bene's reply, which rather confirms our estimate of 

 his article and shows his faith in the declaration on his invoice of its conforming to the 

 requirements of the Federal food and drugs act. 



The letter of Mr. John Bene referred to reads as follows : 



Your letter of the 28th instant to hand with inclosures, and in reply the hydrogen 

 peroxid I supply you conforms strictly to the U. S. P., and the test as outlined by 

 Dr. Wiley bears this out with the exception of the test for solids, as the U. S. P. allows 

 only 0.030, whereas he makes it much over. I can account for this by his not having 

 used a desiccator, for if it is dried any other way it will take moisture from the air, 

 thereby greatly increasing the residue. I have never put out any peroxid which runs 

 higher in residue than the U. S. P. allows. 



HYDROX CHEMICAL Co. 



We hasten to acknowledge receipt of your analyses of Hydrox peroxid of hydrogen, 

 Hamlin's peroxid of hydrogen, and American peroxid of hydrogen, all of which prod- 

 ucts are manufactured by the chemists of the Hydrox Chemical Co. 



We believe it is pretty well demonstrated that acetanilid, ^ grain to the fluid 

 ounce, acts as a preservative to this preparation (as is demonstrated by your analyses) 

 so that the last drop in any container is full U. S. P. strength, making the preparation 

 thoroughly dependable in the hands of the practitioner at all times. 



We beg to state that in our investigations we have found that the breaking up or 

 decomposition of acetanilid causes a slight increase in acidity of the product, this 



