ADMINISTRATION OF SALVARSAN AND NEOSALVARSAN 861 



3. The water should be hot; a good plan is to place 50 c.c. in a medium- 

 sized (250 c.c.) Erlenmeyer flask and bring to the boiling-point. A mix- 

 ing cylinder may be used instead. The ampule containing the drug is 

 wiped off with alcohol, the neck filed across and broken off, and the con- 

 tents gradually dusted on the surface of the water. If the entire contents 

 of the ampule are emptied into the water in a bulk, gelatinous masses 

 may form which dissolve with difficulty. The solution is now neutralized 

 by adding a 15 per cent, solution of caustic soda drop by drop. This neutral- 

 ization is very important, as the toxicity of the acid solution is extremely high. 

 The sodium hydrate solution should be kept in a non-soluble glass con- 

 tainer, made preferably of Jena glass, in order that no constituents of 

 the glass be dissolved with the formation of a sediment. 



A heavy yellowish precipitate is produced by the addition of the 

 alkali, which clears up when sufficient alkali has been added; it is un- 

 desirable to add any more alkali than is exactly necessary to clear the solu- 

 tion, as an excess thereof increases the irritative effect of the preparation. 

 (If too much alkali has been inadvertently added, the excess can be 

 neutralized by the addition of a few drops of a 10 per cent, solution of 

 chemically pure hydrochloric acid. If the acid produces a cloud, this 

 can again be cleared by a drop or two of alkali.) When doubt exists 

 concerning the reaction of the solution, red and blue litmus-paper should 

 be employed. The amount of alkali necessary is about 4 drops of a 

 15 per cent, solution for each 0.1 gm. of salvarsan; thus, for 0.6 gm., 

 1.14 c.c., or about from 23 to 45 drops of 15 per cent, solution of caustic 

 soda, would be required. Citron gives the following table: 



0.2 gm. salvarsan requires 0.38 c.c. of 15 per cent, sodium hydroxid = 8 drops. 

 0.3 gm. salvarsan requires 0.54 c.c. of 15 per cent, sodium hydroxid = 12 drops. 

 0.4 gm. salvarsan requires 0.76 c.c. of 15 per cent, sodium hydroxid = 15 or 16 drops. 

 0.5 gm. salvarsan requires 0.95 c.c. of 15 per cent, sodium hydroxid = 19 or 20 drops. 

 0.6 gm. salvarsan requires 1.14 c.c. of 15 per cent, sodium hydroxid = 23 to 24 drops. 



A drop more of the alkali than is just necessary to produce the clear 

 solution should be added. If this is not done, on cooling the solution 

 may show a precipitate; this can be redissolved by the addition of a 

 drop of alkali. When ready for use the solution should be slightly alka- 

 line. When the solution is neutralized, water should be added to increase 

 the quantity to 200 c.c. for 0.6 gram of the drug or to 150 c.c. for 0.4, 

 although the drug if injected slowly may be given in 30 to 50 c.c. 



I do not believe that any advantage is gained by the employment 

 of salt solution instead of distilled water. If this is preferred, the sal- 

 varsan should be first dissolved in distilled water, neutralized, and then 

 a sterile 0.5 per cent, solution of chemically pure sodium chlorid added 

 to make up the desired volume. 



