October 4, 1906] 



NA TUKE 



579 



said that centuries ago gifts were given for the promolion 

 of objects equivalent to those which modern universities 

 hold in view, which, considering the pecuniary resources 

 of those who gave them, should put our most open-handed 

 modorn millionaires to shame. England has been remiss 

 of late in perceiving and promoting those interests that 

 hinge on scientific and medical research. In this direction 

 Germany has stolen a march upon us, for the various 

 Governments in that Empire have unstintedly provided their 

 universities wilh fully-equipped research laboratories, 

 organised and conducted by professorial directors. A uni- 

 versity is something more than a medical school, a work- 

 shop of research, or a home of science. It must have 

 loftier aims than material advancement or commercial 

 prosperity. It must provide for culture in its widest sense, 

 afford intellectual guidance, encourage individuality, take 

 cognisance of the theoretical problems that arise in the 

 progress of civilisation, be a storehouse of knowledge, and 

 a gymnasium for the exercise of all the powers of the 

 mind ; and to be truly a university it must be an organism, 

 and not a mere conglomeration of parts. The one great- 

 objection to the multiplication of universities is that they 

 may tend to become local seminaries, somewhat parochial 

 in spirit, and fed exclusively from one district, for it would 

 be a misfortune to a boy to pass from a secondary school 

 to a university in the next street, where he would meet as 

 his fellow-students only his old schoolfellows, and where, 

 however amply fed with knowledge, he would still be 

 surrounded by the same traditions and associations and 

 shop amongst which he had been brought up. A provincial 

 university is a contradiction in terms. What is wanted is 

 a group of territorial universities, each with distinctive 

 features of its own, specially adapting it to its environ- 

 ment, but all affording the most liberal instruction, the 

 finest culture, the best intellectual discipline of the day, 

 and collectively meeting the higher educational needs of 

 the whole country. 



SOCIETIES AND ACADEMIES. 

 London. 



Royal Society, Tune 2ft. — " Regeneration of Nerve.=." By 

 Dr. F. W. Mott, F.R.S., Prof. W. D. Halliburton, 

 F.R.S., and .Arthur Edmunds. 



Five sets of experiments are recorded as a contribution 

 to the discussion as to whether the regeneration of nerve- 

 fibres is autogenetic or not. The experimental methods 

 approach the subject in different ways, and in no case was 

 any evidence forthcoming of auto-regeneration. 



The facts recorded, taken in conjunction with those pub- 

 lished by such observers as Cajal and Langley and Ander- 

 son, form, on the other hand, strong pieces of evidence in 

 favour of the Wallerian doctrine that new nerve-fibres are 

 growths from the central ends of divided nerve trunks. 

 The experimental facts recorded by those who, lil<e Bethe 

 and Kennedy, hold the opposite view, are susceptible of 

 easy explanation, mainly on the lines emphasised by 

 Langley and Anderson, of accidental and unnoticed con- 

 nection of the peripheral segments with the central nervous 

 system by means of other nerves cut through in the oper- 

 ation. If such connection is effectually prevented, real 

 regeneration of structure and restoration of function never 

 occur. 



Moreover, the regenerated fibres always degenerate in a 

 peripheral direction, and in a peripheral direction only, 

 when the link that binds them to the central nervous 

 system is again severed. Perhaps the most striking of the 

 facts brought out in the present paper is in reference to 

 the development of the medullary sheath ; this appendage 

 of the axis cylinder appears earliest at situations near the 

 point where the ends of a nerve have been joined together, 

 and reaches the distal portions later. 



What takes place in the peripheral segment of a divided 

 nerve is a multiplication, elongation, and union into long 

 chains of the neurilemmal cells. The same change is even 

 more vigorous at the central termination of the cut nerve; 

 and the view of the phagocytic and nutritive function 

 attributed to this sheath has been supported independently 

 by some striking observations of Graham Kerr which are 

 referred to. At the central end this nutritive function is 



NO. 1927, VOL. 74] 



effective, and provides for the nourishment of the actively 

 lengthening axis cylinders. At the peripheral end, unless 

 ihc axons reach it, it is ineffective in so far as any real 

 new formation of nerve-fibres is concerned. If, however, 

 the axons reach the peripheral segment, the work of the 

 neurilemmal cells has not been useless, for they provide 

 Ihe supporting and nutritive elements necessary for their 

 continued and successful growth. The neurilemmal activity 

 appears to be essential, for without it, as in the central 

 nervous .system, regeneration does not take place. 



According to Graham Kerr, the formation of neuro- 

 fibrilL-E may possibly lake place in the protoplasmic residue 

 of the degenerated axis cylinder; accordmg to Marinesco, 

 this property is assigned to the neurilemmal elements them- 

 selves, a proposition which is extremely improbable, seeing 

 that these elements are mcsoblastic. In either case these 

 two observers consider that the neuro-fibrilla?, however 

 formed, are ineffective until they are activated by union 

 with those of the central axons. The present observations 

 do not entirely exclude this view, but, on the other hand, 

 they lend it no support. The facts are readily explicable, 

 however, on the theory that the nerve-fibres are growths 

 from the central ends of divided nerves. 



" The lonisation produced by Hot Platinum in Different 

 Gases." By Prof. O. W. Richardson. Communicated 

 by Prof. J. J. Thomson, F.R.S. 



The present paper forms an account of an experimental 

 investigation of the steady positive ionisation produced by 

 hot bodies, platinum being assumed to be typical. 



The following are the chief results : — 



The positive ionisation, i.e. the number of positive ions 

 produced by i sq. cm. of platinum surface per second, 

 possesses a minimum value, which depends on temperature 

 and pressure, in most gases. The positive ionisation in 

 oxygen at a low pressure (less than i mm.) is much greater 

 than in the other gases tried. In oxygen at low pressures, 

 and temperatures below 1000° C, the ionisation varies as 

 the square root of the pressure ; at higher temperatures and 

 low pressures it varies nearly directly as the pressure ; 

 whilst at higher pressures at all temperatures the variation 

 with pressure is slower, so that at pressures approaching 

 atmospheric the ionisation becomes practically independent 

 of the pressure. 



The variation with pressure in air is similar to that in 

 oxygen. In nitrogen and hydrogen the ionisation appeared 

 to increase more rapidly with the pressure at high pressures 

 than in oxygen. In very pure helium at low pressures 

 there was a positive ionisation which was a function of 

 the pressure. 



The experiments on ionisation by collisions indicate that 

 the positive ions liberated by hot platinum in o.xygen are 

 of the same order of magnitude as those set free by the 

 collisions. 



The positive leak in oxygen always oscillated around a 

 certain value under specified conditions. It was, therefore, 

 never steady, so the minimum values were taken. This 

 variability was much less marked in the other gases. 



The minimum value of the positive ionisation was found 

 to remain practically constant with a wire heated during 

 three months at various times (for 150 hours altogether) 

 in oxygen at qoo°-iooo° C. Moreover, four different wires 

 of different dimensions after continued heating in oxygen 

 gave nearly the same value for the ionisation at the same 

 temperatures and pressures. 



The positive ionisation in air at constant temperature 

 is smaller than that which would be obtained if the nitrogen 

 were withdrawn, so as to leave only oxygen at a low 

 pressure. The nitrogen, therefore, exerts an inhibiting 

 effect on the oxygen. 



The minimum value of the positive ionisation at a 

 definite pressure in all gases appears to be connected with 

 the temperature by the relation first deduced by the author 

 for the negative ionisation. This relation may be written 

 /= Afl*c~C''2«, where 1 is the ionisation, 8 is the absolute 

 temperature, and A and Q are constants. The value of 

 the constant Q, which is a measure of the energy associated 

 with the liberation of an ion, is in most cases smaller for 

 the positive than for the negative ionisation. 



These results refer to wires which have been heated in 



