358 PHARMACEUTICAL BACTERIOLOGY 



uncertainty as to the results that the method cannot as yet be recom- 

 mended for practical use. 



The addition of disinfectants to medicines for purposes of sterilization 

 has recently received some attention. The use of formaldehyde, ether, 

 chloroform and alcohol, have been recommended, each having its special 

 use in practice. The general criticisms made regarding the use of the ultra- 

 violet rays also apply here. Currie recommends a formalin method as fol- 

 lows: applicable to infusions of calumba, gentian, quassia and senega. 

 "The infusions of calumba and quassia are simply evaporated to one- 

 eighth of their bulk, filtered, and 4 minims of the ordinary 40 per cent, solu- 

 tion of formaldehyde added to each fluid ounce of the concentrated infusion. 

 On dispensing, the requisite amount is put in a shallow basin and brought 

 sharply to the boil, thus dissipating the formaldehyde. The infusion is 

 then diluted to the normal strength with sterilized distilled water. 

 Infusion of gentian is made from gentian root alone, and concentrated. 

 To this is added essence of lemon (i in 10), and the official tincture of 

 orange in the proportion of 2 fluid drams of the former and i fluid ounce of 

 the latter to each pint of the infusion. There is also added 4 minims of 

 40 per cent, solution of formaldehyde to each fluid ounce of infusion. 

 Infusion of senega is concentrated by evaporation and to prevent precipita- 

 tion, 5 grains of potassium bicarbonate are added to each fluid ounce of the 

 concentrated solution, and 4 minims of 40 per cent, solution of formal- 

 dehyde. In case of both gentian and senega infusion, the formaldehyde 

 is dissipated at the time of dispensing, in the manner already described. 

 The advantages of this process are ease of manipulation, cheapness, and 

 the certainty of the antiseptic condition of the infusion while being kept in 

 stock and until dispensed. The quantity of formaldehyde remaining in 

 the diluted infusion is infinitesimal, and may be ignored for all practical 

 purposes." 



It is known that weak solutions of hypodermic and intravenous solu- 

 tions, unless sterilized, will show numerous bacteria upon standing for a 

 time. One per cent, solutions of pilocarpin, atropin, cocaine, morphine, 

 and fluid-extract of ergot have been found to contain millions of bacteria 

 per cc. However, 10 per cent, iodoform glycerin, camphorated oil (i in 10, 

 solutions of apomorphin (0.2 in 20), quinine (i in 10), antipyrin (5 in 10), 

 cocaine (10 per cent.) are usually quite free from bacteria. In a general 

 way the bacterial content of medicinal solutions decreases directly with the 

 degree of concentration. Pus microbes die at once in ether and in a 

 saturated solution of quinine, whereas they remain active in a 10 per cent, 

 solution of cocaine. A 2 per cent, solution of morphine kills pus microbes 

 in twenty-four hours, while pure glycerin kills them only after an exposure 

 of six to eight days. 



