1835.] Scientific Intelligence. 157 



the urine, which is acid in man, is acid in the dog and cat, but alka- 

 line in the horse and rabbit. The remarkable facts which Dr. Donne 

 has observed, and which deserves attention, is, that the sweat, during 

 disease in the human subject, becomes often neutral, and even com- 

 pletely alkaline. He has principally noticed this modification in 

 chronic diseases, and has obtained, in these cases, good results from 

 the employment of the vapour bath. 



2. Mucous membranes. — Under this division may be included the 

 saliva, which in man, while healthy, is decidedly alkaline. This state 

 is generally ascribed to' the presence of lactates and muriate of soda ; 

 the saliva also when evaporated, and the residue crystallized, appears 

 to contain muriate of ammonia. It has been said that the saliva is 

 alkaline during mastication, and that it becomes neutral after eating. 

 Donne denies the accuracy of the latter statement, and affirms that 

 it always in the healthy state turns reddened turnsol paper to a blue 

 colour. In all those animals which Donne has examined, he has 

 found the saliva alkaline. 



He has observed acid in a great number of cases of gastritis or 

 inflammation of the stomach, which has been verified by the applica- 

 tion of tests, and afterwards by inspection of the stomach after death. 

 He has seen several instances in which the saliva acquired its natural 

 or alkaline re-action by anti-phlogistic treatment, and has never 

 observed an acid re-action when the patient possessed a good appetite 

 and unimpared digestion. 



The mucus of the oesophagus as far as the cardiac orifice of the 

 stomach appears to be neutral, at least during digestion. The mucous 

 membrane of the stomach, it has been concluded, from the researches 

 of Prout, Gmelin, and Tiedemann, secretes an acid fluid. 



It is certain that if we examine the liquid contained in the stomach, 

 after all the contents of that viscus have been removed and its parietes 

 well washed we find it strongly acid. This has been explained by 

 Dr. Thomas Thomson, on the idea that common salt is decomposed 

 in the blood by the nerves of the stomach, and that the free acid thus 

 engendered is transmitted to the stomach. The whole""surface of the 

 stomach affords an acid re-action. At the beginning of the duode- 

 num, an alkaline re-action is evinced and appears through the whole 

 of this inferior portion of the digestive canal. This has been accounted 

 for^by supposing that the picromel acts as a base to the muriatic 

 acid and forms a salt. Donne, however, considers that the mucous 

 surfaces secrete an acid liquid. The liquid secreted by the pancreas 

 was found sometimes acid and sometimes alkaline by Tiedemann 

 and Gmelin. Yet by Leuret and Lassaigne, it was found to possess 

 all the characters of saliva. 



The bile is alkaline. The mucous membrane of the urethra, pre- 

 puce and gland, afford an alkaline mucus. The nasal and bronchial 

 mucus present the same characters. 



3. The serous membranes, as the peritoneum, the pleura, arach- 

 noid and synovial membranes, secrete an alkaline liquid, containing 

 muriate of soda, and corresponding with the serum of the blood. 



This liquid in some cases becomes acid. The tears and the 

 humors of the eye are alkaline. From these facts it appears that 

 we may consider the human body as existing between two mem. 



