ART. IV. 2. 6. 9. SORBENTIA. 55 



whole exa6Uy fixteen ounces. Hence there are four grains of 

 arfenic in every ounce of the folution. This (hould be put into a 

 phial of fuch a fize of the edge of its aperture, that fixty drops 

 may weigh one dram, which will contain half a grain of arfenic. 

 To children from two years old to four he gives from two to five 

 drops three or four times a day- From five years old to feven, 

 he direcls feven or eight drops. From eight years old to twelve, 

 he directs from feven to ten drops. From thirteen years old to 

 eighteen he diredls from ten to twelve drops. From eighteen 

 upwards, twelve drops. In fo powerful a medicine it is always 

 prudent to begin with fmaller doles, and gradually to increafe 

 them. 



A faturated folution of arfenic in water is preferable I think 

 to the above operofe preparation of it ; as no error can happen 

 in weighing the ingredients, and it more certainly therefore pof- 

 fefTes an uniform ftrength. Put much more white arfenic re- 

 duced to powder into a given quantity of diftilled water, than 

 can be difiblved in it. Boil it (of half an hour in a Florence 

 fiafk, or in a tin fauce-pan ; let it (land to fubfide, and filter 

 it through paper. My friend Mr. Greene, a furgeon at Bree- 

 wood in Staffordfhire, allured me, that he had cured in one fea- 

 fon agues without number with this faturated folution ; that he 

 found ten drops from a two-ounce vial given thrice a day was 

 a full dofe for a grown perfon, but that he generally began 

 with five. 



9. The manner in which arfenic afts in curing intermittent 

 fevers cannot be by its general ftimulus, becaufe t no intoxication 

 or heat follows the ufe of it ; nor by its peculiar ftimulus on 

 any part of the fecreting fyftem, fince it is not in fmall dofes 

 fucceeded by any increafed evacuation, or heat, and muft there- 

 fore exert its power, like other articles of the ibrbentia, on the 

 abforbent fyftem. In what manner it deftroys life fo fuddenly 

 is difficult to underftand, as it does not intoxicate like many 

 vegetable poifons, nor produce fevers like contagious matter. 

 When applied externally it feems chemically to deftroy the part 

 like other cauftics. Does it chemically deftroy the ftomach, 

 and life in confequence ?. or does it deftroy the adlion of the 

 ftomach by its too great ftimulus, and life in confequence of the 

 fympathy between the ftomach and the heart ? This laft appears 

 to be the mod probable mode of its operation. 



The fuccefs of arfenic in the cure of intermittent fevers I fuf- 

 pe6l to depend on its (timulating the ftomach into ftronger ac- 

 tion, and thus, by the aflbciation of this vifcus with the heart 

 and arteries, preventing the torpor, of any part of the fanguif- 



VOL. I. T T t erotrs 



