6 TECHNICAL DRUG STUDIES. 



were not calculated, but it is plainly evident from the data obtained 

 that there was a great difference between the amount of hydrogen 

 peroxid claimed and the amount actually present. 



Leffmann and Beam a in 1892 published the results of an examina- 

 tion of original packages of a number of brands and their report 

 reflected credit on the material then on the market. The acidity 

 of 50 per cent of the samples, however, was excessive. The number 

 of volumes varied from 9.02 to 15.6. It appears that the potassium 

 permanganate method at the time this investigation was made was 

 fairly well established, as is indicated by the folio whig statement made 

 by Leffmann and Beam: "The proportion of hydrogen dioxid is 

 expressed, as is customary, in volumes of oxygen determined by the 

 standard method with potassium permanganate." Two years later 

 Leffmann 6 examined 21 original packages, in which the amount of 

 available oxygen varied from 1.1 to 11.1 volumes. After making the 

 first determination of available oxygen, the packages were set aside 

 for several weeks at a temperature of 20 C., and then reexamined, 

 the results showing that but little change had taken place. In a 

 number of cases the amount of available oxygen had increased, 

 which is not an uncommon observation, and is due to the fact that 

 the water is more volatile than the hydrogen peroxid. In 1895 c 

 Leffmann reported on the quality of hydrogen peroxid used in filling 

 prescriptions and as supplied to the dental profession. Prescrip- 

 tions calling for 1 ounce were filled by druggists in various sections 

 of the city and samples were also obtained from several dental-supply 

 offices. Leffmann notes particularly the inferior character of the 

 goods supplied to the dental profession. 



The most comprehensive examination of hydrogen peroxid made 

 hitherto was reported by Smith and Oerte d in 1892, including 

 50 samples, representing all of the available brands at that time on 

 the market. One-ounce samples in glass-stoppered bottles were 

 purchased in New York City, and in New Haven, Hartford, and 

 Bridgeport, Conn. The first examination was made within 24 hours 

 after the sample was purchased, and the amount of available oxygen 

 found varied from none to 8.86 volumes. These investigators made 

 the following observations on their findings: 



Reviewing the results, it is seen that 56 per cent of the samples contained from 2 to 

 2.5 grams of the dioxid in 100 cc, or this percentage yielded from 7 to 9 volumes of 

 oxygen. Solutions of this strength, therefore, may be taken as representing the better 

 class of preparations with which we have gained our therapeutic knowledge. That 

 8 per cent of the samples contained no hydrogen dioxid, and that 36 per cent more 

 must be regarded as deficient, inasmuch as they contained less than 2 per cent of 

 hydrogen dioxid, shows very clearly that more care is needed in dispensing this agent. 



a Medical News, 1892, 60: 404. c Intern. Dental J., 1895, 16: 78. 



b Medical News, 1894, 64: 288. <* New York Med. J., 1892, 66: 147. 



