( 184 ) 



In order (u discover lo what extent tlie weiglit of the seed and 

 its adiiesion lo the moist merciiry-snrface could be the cause of this 

 penetration, Pinot devised the following experiment, described in the 

 extract of his letter. A silver needle rested in the middle very movablv 

 on an axis. On one end a germinating Ijathvrns seed was stuck, 

 OJi tlie other end a movable pellet of wax, just balancing the seed. 

 The seed Imng about two milliuietres al)ove a moist niercurv-surface; 

 a bell-jar again kept the air moist. The germination now proceeded 

 somewhat more sh)wly, but tiie root still reached the mercurv-surface; 

 next it forced itself into the mercury, as in tlie case of the unsup- 

 ported seeds, without pushing the balance-arm uj)\vai'ds. For this 

 experiment Latlnrus was chosen l)ecause with it the cotyledons 

 remain within the coats of the seed. Neither could the weight cause 

 the penetration as it was balanced by the wax-[)ellet and also adhesion 

 between the cotyledons and the meicury was excluded as they did 

 not touch each otiier. 



PixoT ga\e the facts as he observed them but he did not venture 

 an explanation. That he would not have been averse to using the 

 vital force for it, liowever, appears from the mention he makes of 

 tiie sulphuric acid: as soon as he kiiled the germinaliug plant l>y 

 it, the root came to the surface of the mercury. 



PiNOT also communicated his discovery to the "Société de Phar- 

 macie de Paris", which gave an extract of his letter in the Bulletin 

 of the transactions of its meeting of August 15, 1820. ^) The same 

 article is found in Flora of that year ''), in the Edinburgh New 

 Philos. Journal '') and in the Annalen der Gewacliskunde ''). 



These j)ublications drew general attention, firstly because it appeared 

 from them that i-oots grow downwards \\ith great force and secondly 

 because it remained unexplained how the seeds found a point ot 

 resistance against the upward pressure of the mercury. This latter 

 point occupied more particularly Pinot's countrymen, whereas some 

 foreign workers were especially struck by the former. Among these 

 Claas Mlldi-;]? of Franeker repeated the experiments and gave a 

 translation of Pinot's article in the Revue Bil)liograplii(]ue together 

 with the description of his own experiments in the autumn of 1829. ^) 



1) Journal de Pharmacie et des sciences accessoires, T. XV 18:29 pag. 490 — 491. 



-) Flora Oder Botanische Zeitung, XII^^'' Jabrgang Zweiter Band 1829 pag. 

 G87 — 688. 



3) The Edinburgh New PbilosopbicalJournal, July — October 1829 pag. 376 — 377. 



■*) Annalen der Gewachskunde, Bd. IV pag. 407 — 408. 



^) Bijdragen tot de natuurkundige Wetenschappen, verzameld door H. C. van 

 Hall, W. Vrolik en G. J. Mulder. Vierde deel 1829 pag. 428—437. 



