GERMICIDAL ACTION OF GASTRIC JUICE 229 
From the facts secured, this author states that strong smokers (con- 
suming more than one dozen cigars a day) seldom have dental caries. 
Dunnon (1902) found no bactericidal action on B. tetanus, B. typhi or 
Leptothrix bucchalis and staphylococcus. Bacillus tuberculosis was 
inhibited. The action was not due to the nicotine content but to 
products of combustion. Arnold (1907) compared the bactericidal 
activity of hay and tobacco smoke. Rideal (1903) reported a slight 
bactericidal action of tobacco smoke. Ellis (1909) has stated that any 
beneficial effects resulting from the use of tobacco, is easily overbalanced 
by the habit of spitting so prevalent among smokers. 
Tue STOMACH 
The bacteriological aspects of the stomach have been concerned 
mostly with its diseases. The bacteria of the stomach gain entrance 
with the food and drink. The germicidal action of the saliva may 
probably be neglected as a factor influencing the number of bacteria 
passing through the mouth. 
Germicidal Action of Gastric Juice. The gastric juice is the normal 
secretion of the stomach. It contains between 2 to 3 per cent solids 
and about 0.2 per cent of free hydrochloric acid, which is the most 
powerful of any acid combination in the stomach. A condition of hyper- 
acidity exists when a decidedly greater amount of hydrochloric acid is 
present than normally, and hyperacidity when the amount of acid is 
below normal. During conditions of hypoacidity, fermentation may be 
active with the formation of lactic and butyric acids. Some hold that 
gastric ulcer and gastric catarrh may be due to a reduced acidity. 
That the gastric juice is germicidal was noticed by Spallanzani in 
1734. When he moistened meat with gastric juice, it did not putrefy. 
Meat which was not so treated but which was moistened with other 
substances, such as water, developed a putrid odor very quickly. He 
opened a snake eighteen days after it had swallowed a lizard and while 
the lizard was partly digested, it had not decomposed. Other experi- 
ments by this early scientist demonstrated that putrefaction could be 
stopped by gastric Juice. 
Koch (1884) fed cholera vibrios to dogs and after a few hours found 
that they. had been destroyed. He stated that cholera vibrios were 
destroyed in the stomach under normal conditions and that if they 
passed through, it was due to some abnormal condition. Falk (1883) 
secured no action on B. tuberculosts. Kurloff and Wagner (1889) 
found a selective action of the gastric juice. Cholera vibrio, B. typhi 
