S38 APPLIED IMMUNOLOGY 



bitis, etc. A dry sterile gauze dressing following the removal 

 of the needle completes the operation. 



A too rapid introduction of the solution naturally might 

 cause dilatation of the right heart with its attendant re- 

 sults. Too much care cannot be exercised to exclude air 

 bubbles from the apparatus, although the danger from air 

 embolism is not great — incomparable in comparison with the 

 advent of air through the great veins of the neck, where a 

 negative pressure exists — it is nevertheless a serious concern. 

 Similarly, the filtration of all solution entering the vein is a 

 matter of importance, lest solid particles of matter, as 

 glass, acting as emboli, might exert a harmful effect. Throm- 

 bosis is an accident alleged to have occurred. This must 

 supervene only as a result of faulty technic or in the presence 

 of an infection and emphasizes the necessity of thorough 

 sterilization of all apparatus and material employed. It 

 is assuredly more likely to ensue when the vein is exposed, 

 due to atmospheric influence on the blood and to metabolic 

 changes in the vein wall. In an experience covering several 

 thousand administrations, it is a complication which we have 

 never encountered. 



Preparation of Neosalvarsan Solution. — The solution 

 of neosalvarsan is slightly less trouble to prepare than 

 salvarsan, since when dissolved it is at once neutral and 

 needs no addition of alkali to counteract the acidity. It is 

 far more unstable than salvarsan, consequently must be 

 used immediately after preparation. Moreover, the solution 

 must never be heated. In fact, it is emphatically stipulated 

 that the temperature of the freshly distilled water or salt 

 solution must be that of the room, that is, 68° to 7^° F. 

 This had best be determined by an appropriate thermometer 

 (T, Fig. 61). Undue shaking is also to be avoided. 



The content of the full adult dose, 0.9 gramme, is dissolved 



