May i, 1S84] 



NA TURE 



It will be seen that the two first cms produced no effect 

 comparable to that caused by c. Cut A was 3 mm. deep, 

 cut b was also 3 mm. deep on the opposite side, so that, 

 after b had been made a bridge, 5 mm. in radial direction 

 remained ; nevertheless the rate of absorption was undi- 

 minished. Cut c was made by increasing B to the depth 

 of 5 mm. from the bark, so that the bridge of more or 

 less central wood finally left was 3 mm. in radial thick- 

 ness, and even then the diminution was only temporary. 

 The cuts were made about 7 cm. from the basal end, and 

 the same distance from the first branch. Another branch 

 of Portugal laurel showed the same thing. The wood of 

 the branch at the point cf section was about a centimetre 

 in diameter, and contained a large proportion of old 

 brown wood. The external envelope of white wood was 

 cut away with the exception ' of a bridge measuring 

 roughly 3 X 3'5 mm. in cross section. 



The result is shown in the following table : — 



i 3+ 



2 13 



16 



I9l 



211 



26 



32 



39 



47 

 53 



Rale of 



15 



cut 

 10 

 11 

 13 

 14 

 13 

 H 

 15 



Here again we have a diminution followed by gradual 

 rise. 



When the little bridge of younger wood was severed, 

 the fall in rate of absorption was rapid. 



h. m ; 

 5 27 



28J 



'. 32 

 47 



Rate of 



js" 1 " " 



bridge severed 



... ... CI2 



o-oS 



Thus the absorpt ; on fell to one-twentieth of the original 

 amount ; that it did not quite cease may be accounted 

 for by the fact that the younger circumferential wood was 

 not completely cut through. 



My apparatus would be also suitable for such experi- 

 ments as those of Dufour {Arbeiten d. Bot. Inst, in 

 Wiirzburg, 1884, Band iii.), in which he showed that 

 sharply bending a stem, such as a hop-bind, does not 

 prevent the passage of the water of tran-piration, whereas 

 water could not be mechanically forced through the bent 

 stem. Dufour also repeated Hales' experiments in which 

 the transpiring branch was cut half through on two oppo- 

 site sides, the points of section being an inch or two apart. 

 When this had been done, so that the continuity of all 

 cavities of vessels and cells was broken, he found that 

 the transpiration-stream could still pass, because the con- 

 tinuity of the cell-Walls remained unbroken. I give a 

 single experiment of this kind to show that my instrument 

 is well adapted for such work (April 15 : — 



11 .32 



34 



36 



37i 



39 



49 



55 



12 2 



Rate of 



Absorption 



25 



25 



25 



first cut 



22 



24 



second cut 



Both cuts penetrated to the centre of the branch. The 

 first was one and a half inch from the base, the second 



' The young wood was not well severed, and a small amount remained in 

 continuity. 



half an inch below the first cut, and on the opposite side 

 of the branch. 



Dufour's experiments would seem to show that the great 

 depression in absorption which o-curred on making the 

 ;econd cut may have been only a temporary phenomenon ; 

 this and other k ndred questions I hope soon to be able 

 to work out. Francis Darwin 



Cambridge, April 17 



WHAT IS A LIBERAL EDUCATION /' 

 T DO not intend, in the present paper, to enter upon the 

 •*• disputed question between the advocates of classical 

 culture on the one hand, and those of scientific training 

 on the other ; because it seems to me that the line on 

 which the two parties divide is not that which really 

 divides the thought of the day. If we look closely into 

 the case, we shall see that the objects of a higher educa- 

 tion may be divided into three classes, instead of the two 

 familiar ones of liberal and professional. In fact, what 

 we commonly call a liberal education should, I think, 

 have two separate objects. With the idea of a profes- 

 sional education we are all familiar : it is that which 

 enables the possessor to pursue with advantage some 

 wealth-producing specialty. Although, in accordance 

 with well-known economic principles, it is designed to 

 make the individual useful to his fellow-men, the ultimate 

 object in view is the gaining of a livelihood by the indivi- 

 dual himself. On the other hand, the object had in view in 

 what is commonly known as culture is not the mere gain- 

 ing of a livelihood, but the acquisition of those ideas, 

 and the training of those powers, which conduce to the 

 happiness of the individual. From this point of view 

 culture may be considered an end unto itself. 



The third object which we have to consider is only 

 beginning to receive recognition in the eyes of the public. 

 It is the general usefulness of the individual, not merely 

 to himself and to those with whom he stands in business 

 relations, but to society at large. Modern thought and 

 investigation lead to the conclusion, that man himself, the 

 institutions under which he lives, and the conditions which 

 surround him, are subject to slow, progressive changes ; 

 and that it depends very largely on the policy of each 

 generation of mankind whether these changes shall be in 

 the way of improvement or retrogression. During the 

 next fifty years all of us will have passed from the stage 

 of active life, and the course of events will be very largely- 

 directed by men who are still unborn. The happiness of 

 those men is, from the widest philanthropic point of view, 

 just as important as the happiness of those who now in- 

 habit the earth ; and, in the light of modern science, we 

 now see that that happiness depends very largely upon 

 our own actions. We thus have opened out to us an in- 

 terest and a field of solicitude in which we need the best 

 thought of the time. The question is, What form of 

 education and training will best fit the now rising genera- 

 tion for the duty of improving the condition of the genera- 

 tion to follow it ? 



Let it be understood that we are now speaking, not of 

 the education of the masses, but of that higher education 

 which is necessarily confined to a small minority. So far 

 as I am aware, that fraction of the male population which 

 receives a college education is not far from 1 per cent. 

 To that comparatively small body we must look for the 

 power which is to direct the society of the future, and by 

 their acts to promote the well- or ill-being of the coming 

 generation. Our duty to that generation is to so use and 

 train this select body as to be of most benefit to the men 

 of the future. What is the training required ? I reply- 

 by saying that I know nothing better for this end than a 

 wide and liberal training in the scientific spirit and the 

 scientific method. The technicalities of science are not the 

 first object ; and, so far as they are introduced, it is only 



