3$; MeíiiOriae cJe la Sociedad Científica 



About some Particular Cases. 



(a) Trance. — This consista in the diininutioii of eertain 

 currents, and is a more deep sieep than that effected in nor- 

 mal conditions. Hypnotizere avail tbemselves of severalmeans 

 of fixing orintdbitiüg curren ts(compression of the eyes, sta- 

 ring, gazing at a brilliant object/ or snggestion, tliat is, the 

 inliibiting action of the will on some nervous currents of a 

 particular sort). 



{b) The sleep of nocturnal animáis in the eourse of day 

 isrelated to the action of light and digestión. In México bats 

 have been observed to issue from their dens during eclipses 

 of the sun; gnats flutter in rooms during dáy-time as soon 

 as all doors are shut so as to leave the apartment in the dark.. 

 Everyone han jeen that owlsí cióse their eyelids whenever a 

 vivid light strikes them. 



(c) Muscular Belaxation during Sleep. — I believe that mus- 

 cular eontractions are due to eertain chunges in the volunae 

 of the protoplásmie alveoli. Rhumbler has demonstrated that 

 such is the possible cause of mytosis, and that the rows o£ 

 small alveoli, when these are partly emptied, diminish ín vo- 

 lume and exercise a strong tensión on the ceiitrosomes. The 

 dynamical influence of those changes being wanting when 

 nerves are sleeping, and there are no waves ñor modifications 

 in the intra-alveolar pressure, it is clear that muscles must 

 Tslax. 



The same happens in several pathological cases, under the 

 influence of fatigue or of eertain depressing emotions, etc. 

 This means that I suppose nervous waves to provoke the pas- 

 sage of the alveolar enchylema into the protoplasm of the mus- 

 cles either by the mechanical action of the shock or by an 

 increase of hydrostatie pressure. I do not deny that the lat- 

 ter have the structure and elasticity required. It will be re- 



