May, 1904.] 



KXOWT.F.DGE \- SCIENTIFIC NEWS. 



103 



same effects. These actions would persist after the extinction 

 of the N-rays. as in the case of quartz, though the property of 

 emitting secondary rays does not penetrate liut slowly the 

 m.asses of metal. 



Aluminium, wood, dry and moistened paper, paraffin, &c.. do 

 not show this' property of storing up Nrays. Calcium sul- 

 phide, on the other hand, will exhibit the same effect. This 

 phenomenon accounts for the fact formerly observed by the 

 author that the increase in phosphorescence under the action 

 of N-rays require a cert.ain time both to be produced and to 

 disappear. .-Vs. in fact, N'-rays .are stored up, the different 

 parts of the mass of sulphide 'will mutually strengthen their 

 phosphorescence; as. however, the storing up is progressive, 

 and as, on the other hand, the amount .stored up is not 

 e.xhausted instantaneously, the effect of N-rays falling on 

 phosphorescent sulphide must increase slowly, .and on being 



cords of two brothers, dead of hereditary ataxia. Coloured 

 plates illustrate the lesions of the spin.al cord. 



The article in question is extremely interesting to neuro- 

 logists and medical men, and should be studied by those 

 seeking the truths of well-deep neurological liter.ature. 



To the gener.al scientific reader, who does not wish for 

 technical details, the .article brings home the lessons of care 

 that parents should take in inquiring into the antecedents of 

 those about to m.arry. 



Dr. Sanger Brown says, and truly says : '• Hereditary ataxia 

 is a disease which may be traced through several — at least 

 four — generations, increasing in extent and intensity as it 

 descends, tending to occur earlier in life, .and to advance more 

 rapidly. It usually attacks several members of the same 

 family. It occurs most frequently between the .ages of 16 and 

 35. It shows no marked preference for sex. but it descends 



eliminated their effect cannot but progressively be extin- 

 guished.' 'Certain stones picked up in a court where they had 

 been exposed to the action of sun rays in the afternoon would 

 give off spontaneously N-rays. preserving this activity for four 

 days without any appreciable decrease. The surface of these 

 bodies should, however, be very dry, the slightest layer of 

 water being sufficient to stop the N-rays. 



Hereditary Ataxia. 



Among the latest volumes of the Decennial Publications of 

 the University of Chicago is an interesting article by 

 Lewellys F. Barker,* which includes a detailed description of 

 the gross and microscopic findings in the brains and spinal 



'"A Description of the Brains and Spinal Cords of Two Brothers, 

 Dead of Hereditary Ataxia of the Series in the Family Described by 

 Dr. Sanger Brown," by lewellys F Barker. 'The Decennial 

 Publications of the University of Chicago. 



Family Tree of Hereditary Ataxy. 



through females four times as frequently as through males 

 There is always considerable inco-ordination of all the volun- 

 tary muscles, and a sluggishness of the movements which they 

 produce, when the disease is well established. This is 

 usually noticed first in the muscles of the legs, but in a few 

 months or years extends to the arms, face, eyes, head and 

 organs of speech. Sometimes it occurs first in the upper 

 extremities, and sometimes in the organs of speech." 



There is little to be noticed in the macroscopic appearance 

 of the cord as shown in the illustrations given, but micro- 

 scopically, there is revealed marked degeneration in the grey 

 and white matter. 



The matter contained in this publication is accurate, and 

 shows a profound insight and knowledge of the disease treated. 

 By its study, we are enal)led to know with certainty the 

 neurone-systems principally involved in the individuals who 

 are affected, though we are as yet entirely ignorant as to why 

 just these neurone-systems should be picked out. The letter- 

 press is clear and large, and the plates are extremely well 

 done. We must congratulate the University of Chicago Press 

 Illinois, on the first series of their publications for the 

 University of that city. — S.G.M. 



