526 BACTERIOLOGY. 
Wertheim demonstrated that the addition of peptone 
to the culture medium was an important factor in the 
cultivation of gonococci. Kiefer (1895) proposed a cul- 
ture medium consisting of one part of hydrothorax or 
ascitic fluid and one part of a fluid containing 3.5 per 
cent. agar, 5 per cent. peptone, 2 per cent. glycerin, and 
0.5 per cent. salt. 
Simultaneously with Kiefer, Heiman recommended 
a medium made from hydrocele fluid, or from ‘“ chest- 
serum’’ obtained from a patient suffering from hy- 
drocele or hydrothorax or acute pleurisy. Having 
experimented with all the various culture media here- 
tofore prepared for the cultivation of the gonococcus, 
Heiman believes this medium to be superior to placenta- 
serum, sheep blood-serum, or ascitic fluid, because of 
the large amount of serum albumin which it contains. 
The medium consists of a 2 per cent. agar, plus 2 per 
cent. peptone, plus 0.5 per cent. salt and 2 per cent. 
glucose. Of this mixture two parts are added to one 
part of chest-serum, which is, if necessary, fractionally 
sterilized between 65° and 70° C. for one hour for seven 
consecutive days.. The chest-serum-agar should have a 
neutral reaction. The growth on this medium is thus 
described: In plate cultures streaked on the surface, 
growth abundant, colonies circular in shape, edges 
somewhat irregular, shading off into yellowish-white; 
texture finely granular in periphery, presenting punc- 
tated spots of higher refraction in and around the 
centre of yellowish color (Fig. 70). 
The gonococcus has but little resistant power against 
outside influences. It is killed by weak disinfecting 
solutions and by desiccation in thin layers. In com- 
paratively thick layers, however, as when gonorrheal 
