652 PHILOSOPHICAL TRANSACTIONS. [aNNO 1702. 



most extraordinary observation was that of the inequaHty of the degrees of the 

 meridian on the earth; for he found that going southward one degree surpassed 

 another an 800th part,* which may give great reason to doubt of the exact 

 roundness of the earth. On this occasion he reported two different opinions : 

 the one of M. Huygens and Newton, the other of a mathematician of Stras- 

 burg named Eisenschmid. The two former hold that the earth is flatted to- 

 wards the poles, so that it is something of the shape of a Dutch cheese: which 

 they both conclude by physical and algebraical deductions, from an observation 

 made atCape-Verd, viz. that the pendulums, though of the same length, make 

 their vibrations there much slower than in the northern countries. The other 

 mathematician holds that the figure of the earth is elliptical, so that it is 

 lengthened out towards the poles, having the form of an egg. M. Cassini left 

 the question undecided, -f The cities through which he observed the meridian 

 of Paris to pass, are Dunkirk, Amiens, Aubigny, Bourges, Aurillac, Rodez, 

 Alby, and Carcassone. 



M. Bolduc spoke next. He examined the principles of purgatives, and began 

 with ipecacuanha, which he said he had endeavoured to sweeten and qualify by 

 trying to take away its too great emetic power. He asserted, that howsoever 

 violent ipecacuanha was, yet it is not so dangerous as scammony or coloquintida, 

 which always leaves gripes, and sometimes dysenteries, whereas ipecacuanha 

 leaves only a gentle astriction after it. From ipecacuanha he passed to hellebore, 

 which is another violent emetic; which he distinguished into two sorts, the 

 black and the white. He said, that the white caused mortal convulsions : that 

 the black hellebore, which comes from England, is much weaker than that which 

 grows on the mountains of Switzerland. He said, that having put it in a retort 

 in a reverberatory fire, he at first drew off an acid spirit, next an oily acid spirit ; 

 thirdly a violent alkali spirit came over mixed with oil of tartar, and lastly a fetid 

 oil. That from the caput mortuum he had by a lixivium, a fixed salt, which 

 fermented with acids, such as all other plants give ; besides these operations, he 

 drew an extract of this root with spirit of wine, to get the resinous parts, and 

 with distilled rain water for the saline. He got but very few of the former, but 

 a great deal of the other. Comparing then the effects of these purgatives, he 

 said that the purely resinous purge but little, and with much irritation ; that the 

 purely saline purge only by urine, but that both together purge very well. That 

 it is for this reason that physicians make use of salt of tartar, to correct the bad 



* This irregularity was probably occasioned by errors in the celestial observations, arising from 

 the unequal deviations of the plummet near the mountains and valleys. See the note, p. igs, vol. ii. 

 of this Abridgment. 



f This question was afterwards fully decided in favour of the opinion of Newton and Huygens. 



