

Dr. Thomson on Caries, or Decay of the Teeth. J 33 



from the action of the saliva, which becomes impregnated with acid of 

 different kiuds, either from tho food we occasionally indulge in, or from a 

 morbid state of the stomach, arising from scrofula or other causes. The 

 saliva, acccording to M. Donne, is in its normal state purely alkaline, and 

 this conclusion is now followed by most physiologists. The pathological 

 condition of the stomach, indicated by an acid state of the saliva, is 

 irritation of its mucous membrane, and ho contends that this condition of 

 the stomach uniformly induces or is accompanied by acidity of the saliva. 

 Besides giving the result of his experiments in arriving at these conclu- 

 sions, he has narrated a large number of cases illustrative of the corres- 

 ponding change from acidity to alkalinity, as the patient recovered from 

 disease. 



In compound decay where the disease appears between the teeth, 

 more particularly in the incisors and bicuspides, and exhibits itself as a 

 mere point, gradually increasing till absolute destruction of the organs 

 takes place, the author considers that the disease never takes place till 

 actual contact takes place, and when from the pulp being unhealthy, the 

 enamel has not been properly developed. Hence the apparent cause of 

 further decay is from without, a view which is confirmed by the fact 

 derived from experience, that in nine cases out of ten, compound decay 

 is developed before manhood, at a time when the teeth are very highly 

 organized, and consequently more likely to suffer from any obstruction 

 of the circulating medium. 



The morbid states of the saliva which produce this decay, often arise 

 from a weak constitution, thus laying the foundation of decay in after 

 years; for although a child may become healthy, and apparently the decay 

 may not be distinctly developed, yet a minute investigator will detect it 

 at once. The disease, it is true, may not as yet be active, still the 

 slightest attack of fever or ill health of any kind, by increasing the acidity 

 of the saliva, will be sure to induce a further development of decay. 



A life protecting frame for cleaning windows, made by John Bailie, 

 Edinburgh, was exhibited to the Society by Mr. Liddell, and described 

 by Mr. W. M. Buchanan. 



29*A April. — Tlie President in the Chair. 



Mr. Liddell read a paper on tho statistics of pauperism, crime, and 

 state of education of the juvenile portion of the poor of Glasgow. Tho 

 following table is drawn up from data furnished by the Sunday-School 

 Teachers, by Mr. Alexander Pliimister, jun. 



