( 185 ) 



He took "small bcci'-glasses" of a lilllc iiioi-c liiaii 5 cm.diaiiKMer 

 (MuLüEK ypeak« of N. inches, i. e. new inches or ceiiliinelres) and 

 tilled them with niercniy 4 cm. deep, on which lav a laver of 

 water with pigeon-beans (Vicia faba minima) and bnckwheat. The 

 roots of buckwheat did not penetrate inio Ihe mercury and went on 

 creeping over the surface for a month. When Ihe beans had grown 

 stems of two centimetres, five of them had 1 heir roots in (he mercui-v; 

 the rest lay on the surface but had evidently been submerged. 



In order to prevent capsizing, a few of the seedlings of Vicia 

 were i)icked out wdiicli had straight roots and (hese were s(uck 

 (hrougli holes in a thin slice of cork, floating on the w^ater above (lie 

 mercury. Especially between the wall of the glass and the mercui-v 

 he now^ observed the penetration of the secondary roots. 



His conclusion is that these experimenls afford a new pi\»of iha( 

 the innate tendency of the root to grow downwards, must be con- 

 sidered as a vital action dependent upon infernal force which ex(ei-nal 

 circumstances can hinder, modify and even render almosl irreco'>- 

 nisable, but by no means destroy. ^) 



Mulder thinks only of the force with which the roots grow 

 downiwards. The physical paradox esca|>es his attention, although 

 it was exactly this which was emphasised by Pinot's experimejit 

 with the siher needle. By his using big seeds, seedlijigs in an 

 advanced stage and cork, his experiments differ materially from those 

 of PiNOT. A short accoujit of Mulder's experiments by C. ^Iorren 

 ap])eared in the Revue lUldiographique -) ; also in Linnaea there is 

 an extrtict of his article. ^) 



H. R. GoEPPERT at Hroslau repeated Pjxot's ex|)eri men ts as iMui, der 

 did, when he read an account of them in Fhoriep's No(ize]i fiir 

 Natur- und Heilkunde Nr. 530, Aug. 1829, page J 54. He described 

 his experiments iji an article, entitled: "Uel)er das Keimen der Samen 

 auf (^uecksilber". ') (tOEPPErt used peas and oats ; only the primary 

 roots of the peas made a small depression in the mercury, the other 

 roots crept over the surface. Better than with Pinot's silver balance 

 he thought to eliminate the weight of the seeds by pulling them 

 into the holes of a wooden cross which above the mercuiy was 

 hekl fast in a conically shaped glass. No more than .Mulder he 

 noticed Pinot's })liysical paradox, for the friction of the scimI in the 



^) 1. c. pag. 43G. 



-; Pvevue Bibliographit[ue. Dec. 1830, pag. 120— 13U. 

 •^) Linnaea Bd. 5, pag. 191 of the „Literafur-Bericlil". 



') Verliandluiigon des Vereins zur Belo-derung dcs Gartenbaucs, Vlft'-'i" Band 

 1831, pag. 204-- 200. 



