376 PYOGENIC BACTERIA. 
vented by the agents named in the proportion given: Nitric acid, 
1:797; phosphoric acid, 1:50; boracic acid, 1:327; oxalic acid, 
1 :433 ; acetic acid, 1 : 720; citric acid, 1:433; lactic acid, 1 :350 ; 
benzoic acid, 1:400; salicylic acid, 1:655; iodine dissolved with 
potassium iodide, 1:1,100; arsenite of potash, 1: 733; mercuric 
chloride, 1:81,400; chloral hydrate, 1:133; carbolic acid, 1 : 814; 
thymol, 1:11,000; resorcin, 1:122; hydrochinon, 1:353; kairin, 
1:407 ; antipyrin, 1:26; muriate of quinine, 1:550; muriate of 
morphia, 1:60. For the destruction of vitality very much larger 
amounts are required. In Bolton’s experiments (1887) a one-per-cent 
solution of carbolic acid was successful after two hours’ exposure, 
but two per cent failed to completely destroy vitality in the same 
time ; one per cent of sulphate of copper was also successful, and but 
a single colony developed after exposure to a solution of 1:200. In 
the experiments of Gartner and Plagge the Staphylococcus aureus in 
bouillon cultures is said to have been killed in a few seconds (eight) 
by a solution of mercuric chloride of the proportion of 1: 1,000; Behr- 
ing found it was killed by the acid sublimate solution of La Place, 
in the proportion of 1:1,000, in ten minutes; Tarnier and Vignal 
found that a solution of 1:1,000 was successful in two minutes. 
Abbott (1891) has shown that in the same culture there may be a 
considerable difference in the resisting power of the cocci, and that 
while frequently all are destroyed in five minutes by a 1 :1,000 solu- 
tion, it occurs quite as frequently that some may survive after an ex- 
posure of ten, twenty, and even thirty minutes. 
Pathogenests.—Subcutaneous inoculation with a small quantity 
of a culture of Staphylococcus pyogenes aureus is without result in 
rabbits, guinea-pigs, or mice, but when a considerable quantity is 
injected beneath the skin of a rabbit or a guinea-pig an abscess is 
produced, which usually results in recovery, but may give rise to 
general infection and the death of the animal. Injection into a 
vein or into the cavity of the abdomen in the animals mentioned 
usually induces a fatal result within a few days. The most charac- 
teristic pathological changes are found in the kidneys, which con- 
tain numerous small collections of pus and under the microscope 
present the appearances resulting from embolic nephritis. Many of 
the capillaries and some of the smaller arteries of the cortex are 
plugged up with thrombi consisting of micrococci. Metastatic ab- 
scesses may also be found in the joints and muscles. The micro- 
cocci may be recovered in pure cultures from the blood and the 
various organs ; but they are not numerous in the blood, and a sim- 
ple microscopical examination will often fail to demonstrate their 
presence. 
Animals frequently survive the injection of a small quantity of 
