58 Miss M. P. FitzGerald. The Origin of the [June 4, 
and the tissues immediately examined. No blue colour was visible macro- 
scopically until the stomach was opened. A deposit of Prussian blue was: 
then found on the surface of the mucosa, more particularly in the region 
corresponding to the lesser curvature of the organ. Microscopical examina- 
tion, however, furnished no evidence of the presence of a similar deposit in 
the gland tubules. Bernard therefore concluded that the gastric secretion 
did not acquire its acid properties until it reached the superficial region of 
the mucosa and had mixed with other fluids of the stomach. 
That both the salts had reached the tissues, and were in a condition to allow 
their interaction to form Prussian blue in a suitable medium, was proved by 
their presence in the urine, and the instantaneous occurrence of the 
Prussian blue reaction on the addition to it of either hydrochloric or sulphuric 
acid. Other tissues of the injected rabbit were placed in an acid bath 
(H2SO,); as a result Prussian blue was found in the lymphatic glands of the 
upper part of the neck and in the orifices of the glands of the pharynx. 
Bernard was further strengthened in his belief that the acid was formed 
externally to the glands and on the surface of the mucosa, by the negative 
results obtained in later experiments* ; also, by the fact that after washing the 
mucosa with water, or injecting it with a continuous current of water charged 
with carbonate of soda, the acid reaction reappeared on the surface at the 
end of a certain interval of time depending on the method of procedure. 
This led him to the conclusion that the acidity was due to a fermentation 
of the mucus, and as proof he pointed out that if the non-acid mucus were 
removed and isolated for a short time it would become acid, a result 
excluding any possibility of action by the so-called acid glands. At a still 
later date}+ he regarded the acid as a remote product of the stomach secretion, 
holding the view that the glands secreted a liquid which split up into an acid 
fluid and another undetermined product, and that the appearance of the acid 
on the surface of the mucosa after death, occurring even after the stomach 
had been immersed in a dilute solution of sodium carbonate, was due to a 
continuation of secretion, the secretory processes continuing after death until 
putrefaction causes the impairment of an organ. He also mentions that the 
acid thus found was soluble in alcohol. 
Observations on the reaction of the gastric mucosa of birds were made by 
Briicket in 1859. Experimenting with a living pigeon, he found that the 
reaction of the surface of the mucosa of both the cesophagus and gizzard was _ 
alkaline, but that this was markedly acid in the region of the stomach glands. 
* ‘Gaz. Heb. de Med.,’ 1873, p. 691 ; discussion on paper by Lepine. 
+ C. Bernard, ‘Gazette Médicale,’ Paris, 1877 (‘Soc. de Biol.’), pp. 224 and 261. 
{ Briicke, ‘Sitz. K. Akad. Wiss.,’ Vienna, vol. 37, 1859. 
