342 APPLIED IMMUNOLOGY 



the foot of the bed be elevated 14 to 16 inches for four hours. 

 The patient should continue in bed for two or three days. 

 Repetition of the treatment depends upon the extent and 

 duration of any reactions incurred. As a rule the intra- 

 spinal injections are repeated at intervals of two weeks. The 

 actual number of treatments should depend upon the analysis 

 of the spinal fluid, the object being to obtain a negative Was- 

 sermann reaction, a reduction in the number of lymphocytes 

 to five per cubic millimetre, and a normal globulin content. 



Artificially Salvarsanized Serum, — Attempts have been 

 made to salvarsanize serum in vitro, in the hope of increas- 

 ing the arsenical content in view of intraspinal injections. 

 The results have been disappointing and in the employment 

 of neosalvarsan, notably in Los Angeles, disastrous. 



Recently Fordyce,^*^ adopting the technic of Ogihde, in 

 which a known amount of salvarsan is added to human serum, 

 recommends the following technic : 



" Fifty c.c. of blood are drawn into a centrifuge bottle 

 and centrifuged twice. It is important to have the serum 

 clear and free from fibrin and blood-cells. To obtain the 

 requisite amount of the drug, old salvarsan is mixed in the 

 usual way in the proportion of 0.1 gm. to 40 c.c. of fluid, 

 care being taken not to over-alkalinize ; 0.4 c.c. of this solu- 

 tion is the equivalent of 1 mg., and is taken as the standard 

 for measuring the dosage. For this purpose a 1 c.c. pipette 

 graduated in hundredths should be employed. The desired 

 amount of salvarsan is added to from 12 to 15 c.c. of the 

 serum, shaken to and fro to mix thoroughly, and then placed 

 in the incubator at 37 C. (98.6 F.) for one hour, after which 

 it is inactivated for half an hour at 56 C. (132.8 F.). The 

 latter is a most important step in the technic, as Swift and 



^^Jour. Am. Med. Assn., Aug. 15, 1914, 555. 



