Natural History, 467 



digestion of food ? Is its existence sufficiently proved by the 

 experiments of Spallanzani and Senebier, or is it rendered 

 doubtful by those of Montegre 1 What has been demonstrated 

 in this respect by comparative anatomy, and particularly by 

 opening the stomachs of animals which have been killed either 

 fasting or shortly after taking food ? And supposing the exis- 

 tence of gastric juice in the human body to be well proved, 

 what ought to be avoided in order that its effect on the digestion 

 may not be impeded V* 



4. " How far are we acquainted, from the chemical experi- 

 ments of Vauquelin, with the various species of cinchona; 

 likewise from the experiments and observations of others. 1. 

 What is the different nature and quantity of their constituent 

 parts ? 2. To what particular principle ought we to ascribe the 

 febrifuge powers of cinchona ? 3. What criteria can we de- 

 duce from it, so as to distinguish the best species, and the va- 

 rious barks used as substitutes ? 4. Are any rules to be ob- 

 tained for preserving the principle, in which consists its febri- 

 fuge power, entire in the various preparations of cinchona ?" 



5. " Although a general introduction of vaccination has al- 

 most every where put a stop to the epidemic small-pox, yet 

 within these few years past that disease has re-appeared, both 

 here and elsewhere ; and as a species of variolous pustules have 

 recently shewn themselves in those who have been vaccinated > 

 it is inquired, 1. Of what description are these pustules ? In 

 what do they differ from the real small-pox? Is it the latter 

 that is produced in these individuals who have been previously 

 vaccinated ? Does it arise from constitution, from indisposition, 

 from the matter employed in vaccination, or from other circum- 

 stances, and what is the method of preventing it ? 2. What 

 can be safely asserted, with regard to the duration of the pre- 

 servative virtue of vaccination ? Would it prove of any service 

 to re-vaccinate on the re-appearance of the disease ? Are the 

 methods employed by us for the encouragement of vaccination 

 sufficient, and do they tend to cause the entire disappearance 

 of the small-pox ? In case they are not, what more efficacious 

 ones could be adopted ?'* 



