( ^'^^ ) 



\A;is lo 1)0 ()ltsor\e(l in all (•;is('>. did not l)C('0,nie clear (o inc, wlill 

 1 ^vill jiot )»ass in silener llie Ihcl of llie constant appearance of 

 this üranulation. 



As the snniniarv of mv i-esnlts, 1 liiid that after onesided k'sion 

 of the spinal cord an ascending de^ueneiation is oI>sci-\ed in the 

 followinj^ systems : 



1. Tiie homo-lateral j)osterioi- colnmns, where it may he li-aced 

 as far as into the Jinclei of (JolI; and i>rHi)\(ii. 



2. The lateral fascicnli to the cerebellnm, 



a. the dorsal portion almost withont e\'ce|»lion oidy' on the 



operated side, 

 />. the antero-lateral portion on l)oth sides, hnt still pi'inci- 



pally on the operated side. 



3. Tiie fascicnlns longitndinalis dorsalis on both sides. 



4. The corpns trapezoides on both sides (V) 



The descending degenei-ation is represented in ligni-es 21, 22. 2o 

 and 24. It inclndes: 



i.,The anterior colnmns, principally on the operated side, probably 

 centrifugal fibres from the fasc. long. dors. 



2. The pyramidal latei'al fascicnlns on the operated side. 



3. The tractns rnbro-spinalis, in the lateral colnmns (van (TEnrcHTEN). 



4. De ti'actus vestibnlo-spinalis, frontal of the anterior horn (Edinoer). 



5. Fibres in the posterior colnnnis, being situated partly along 

 the sulcus longitudinalis i)Oslerior. and iiartl\ along tlie entering 

 l)Osterior roots, to all probability })resenting a homologon to the 

 oval area and the comma of Sciu t.tzk. 



Physics. — "}fof/())i of )in>lt'riiJ('-si/sf('w.'i-on irlu'rli ))() (wfj^rnal force.'i 

 dct.'^ l>y Dr. ( ). P()st:\i\. (Communicaied by l^rof. IT. A. 



LORENTZ). 



(C.ommuiiiralcil in the Meeting of Novemlier 30, 1007). 



§ J. Up till now two ways have been mainly followed to show 

 that a gas mass left to itself, on which no external forces act, in 

 consequence of the collisions of liie molecules will finally ]>ass into 

 a state, in which the molecules are probably al)Out uniformly distributed 

 over the vessel and possess Maxwet.l's distribution of velocities. 



The first is the method of I)0T.tzmann, who assuming that the 

 density all ihi-ough the vessel is already the same, and further 

 starting from the assumj)tion that there is no regular ai-rangement 

 of the molecules as regards the velocitv, demonstrates that a cei-tain 



