OXALIC ACID. 47 



/ 



mucus of the gall-bladder, and that it is scarcely ever absent from 

 the mucous membrane of the impregnated uterus. I once discovered 

 oxalate of lime in expectorated matter, but whether it was produced 

 from the pulmonary mucus, or from fragments of food in the mouth, 

 I could not decide. [Dr. Garrod* has recently detected oxalic acid 

 in the blood in a case of chronic hiccup and vomiting, and in 

 several cases of gout. G. E. D.] 



Origin. As the use of vegetable food, of which many varieties 

 contain oxalates, increases the quantity of oxalate of lime in the 

 urine, the inference would seem a legitimate one, that the 

 oxalates are transmitted from the food to the urine. The source 

 of this salt must, however, not be sought for only in the pre- formed 

 oxalates, but in the amount of alkalies in combination with vegetable 

 acids present in the food ; for, as we have already mentioned, they 

 induce an augmentation of the oxalate of lime. In all the well- 

 marked cases to which I have alluded, the increase of the oxalate 

 of lime seemed to be combined with disturbance of the respiratory 

 process. Thus it may easily be understood why, after the use of 

 drinks rich in carbonic acid, of alkaline bicarbonates, or vegetable 

 salts, oxalic acid is increased in the urine ; the superfluous carbonic 

 acid which has entered the blood, or been generated there from the 

 salts of organic acids, must obstruct the absorption of oxygen and 

 the perfect oxidation of certain substances in the blood ; hence also 

 the quantity of oxalate of lime has been found to be increased by the 

 partially impeded exchange of oxygen and carbonic acid in the 

 lungs, consequent on emphysema, pulmonary compression during 

 pregnancy, &c. We might, in such cases, assume, according to a 

 formerly prevalent belief, that the kidneys in some degree acted 

 vicariously for the lungs, since under the form of oxalic acid they 

 remove from the organism the carbon which the latter organs would 

 have excreted as carbonic acid. 



Although certain chemists hold a contrary opinion, it is an 

 undoubted fact that the nervous system has an influence on the 

 oxidation of the blood. The occurrence of oxalate of lime in cases 

 of epileptic convulsions, in convalescent persons, &c., might be 

 referred to the disturbance induced in such cases in the nutrition 

 or in the function of the nervous system, and to its diminished 

 influence on the process of respiration, without there being any 

 necessity for the assumption of a special diathesis. 



It seems, moreover, unreasonable to set up such a diathesis, 

 since the establishment of a special disease from a single symptom 



* Medico-chirurgical Transactions. Vol. 32, p. 171. 



