October 6, 1910] 



NATURE 



445 



wide training, have emphasised the morphological aspect 

 and the readily observable phenomena of living matter ; 

 while the physicist and chemist, knowing little of the 

 morphology of the cell and of its vital manifestations, 

 have been unable to apply satisfactorily the principles of 

 their sciences to an understanding of its processes. The 

 high degree of specialism which certain departments of 

 biology has in recent years developed has made that 

 difliculty greater than it was. 



It must also be said that in some instances in which 

 the physicist and chemist attempted to aid in the solution 

 of biological problems the result, on the whole, has not 

 been quite satisfactory. In, for e.xample, the phenomena 

 of osmosis, the application of Arrhenius's theory of ionisa- 

 tion and van 't Hoff's gas theory of solutions promised 

 at first to explain all the processes and the results of 

 diffusion through animal membranes. These theories 

 were supported by such an array of facts from the side 

 of physics and physical chemistry that there appeared to 

 be no question whatever regarding their universal 

 validity, and their application in the study of biological 

 phenomena was urged with acclaim by physical chemists 

 and eagerly welcomed by physiologists. The result in all 

 cases w'as not what was e.xpected. Diffusion of solutes, 

 according to the theories, should, if the membrane is 

 permeable to them, always be from the fluid where their 

 concentration is high to that in which it is low. This 

 appears to happen in a number of instances in the case 

 of living membranes — or, at least, we may assume that 

 it occurs — but in one signal instance, at least, the very 

 reverse normally obtains. In the kidney, membranes 

 formed of cells constituting the lining of the glomeruli 

 and the renal tubules separate the urine, as it is being 

 formed, from the blood plasma and the lymph circulating 

 through the kidney. Though the excreted fluid is derived 

 from the plasma and lymph, it is usually of much greater 

 osmotic concentration than the latter. 



It may be urged that this and other discrepancies are 

 explained by the distribution (or partition) coefficient of 

 the solutes responsible for the greater concentration of 

 the product of excretion, these solutes being more soluble 

 in the e.xcreted medium than in the blood plasma, and 

 distributing or diffusing themselves accordingly. If such 

 a principle is applicable here as an explanation, it may 

 be quite as much so in other physiological cases in which 

 the results are supposedly due only to the forces postu- 

 lated in the theories of van 't Hoff and Arrhenius. 

 Whether this be so or not, the central fact remains that 

 the enthusiastic hopes WMth which the theories were applied 

 by physiologists and biologists in the explanation of certain 

 vital phenomena have not been wholly realised. 



The result has been a reaction amongst physiologists 

 and biologists which has not been the least contributory 

 of all the causes that have led to the present revival of 

 vitalism. 



Another difficulty in accounting for the vital phenomena 

 has been due, until recently, to a lack of knowledge of 

 the physical and chemical properties of colloids and 

 colloidal " solutions." The importance of this knowledge 

 consists in the fact that protoplasm, " the physical basis " 

 of life, consists mainly of colloids and water. Until 

 eleven years ago, what was known regarding colloids was 

 derived chiefly from the researches of Graham (1851-62), 

 Ljubavin (i8Sq), Barus and .Schneider (1891), and Linder 

 and Picton (1892-7), who were the pioneers in this line. 

 In 1899 were published the observations of Hardy, through 

 whose investigations very great progress in our know- 

 ledge of colloids was made. In 1903 came the invention 

 of the ultramicroscope by Siedentopf and Zsigmondy, by 

 which the suspension character of colloid material in its 

 so-called " solutions " was visually demonstrated. During 

 the last seven years a host of workers have by their 

 investigations greatly extended our knowledge of the 

 physical and chemical properties of colloids, and now the 

 science of Collochemistry bids fair, the more it develops, 

 to play a very important part in all studies bearing on 

 the constitution and properties of living matter. 



Then, also, there are the phenomena of surface tension. 

 This force, the nature of which was first indicated by 

 Segner in 1751, and described with more detail by Young 

 in 1804 and Laplace in 1806 in the expositions of their 



NO. 21.^6. VOL. 84.1 



theories of capillarity, was first in 1869 only casually 

 suggested as a factor in vital processes by hngelmann. 

 Since the latter date and until 1S92, when Biitschli pub- 

 lished his observations on protoplasmic movement, no 

 serious effort was made to utilise the principle of this 

 force in the explanation of vital phenomena. Even to-day, 

 when we know more of the laws of surface tension, it is 

 only introduced as an incidental factor in speculations 

 regarding the origin of protoplasmic movement and 

 muscular contraction, and yet it is, as I shall maintain 

 later on in this address, the most powerful, the most 

 important of all the forces concerned in the life of animal 

 and vegetable cells. 



It may be gathered from all that I have advanced here 

 that the chief defect in biological research has been, and 

 is, the failure to apply thoroughly the laws of the physical 

 world in the explanation of vital phenomena. Because 

 of this too much emphasis is placed on the division that 

 is made between the biological and the physical sciences. 

 This division is very largely an artificial one, and it will 

 in all probability be maintained eventually only as a con- 

 venience in the classification of the sciences. The bio- 

 logist and physiologist have to deal with problems in 

 which a wide range of knowledge is necessary for their 

 adequate treatment ; and, if the individual investigator has 

 not a very extensive training in the physical sciences, it 

 is impossible for him to have at his command all the 

 facts bearing on the subject of his research, unless the 

 problem involved be a very narrow one. The lack of this 

 wide knowledge of the physical sciences tends to 

 specialism, and, as the specialism is ever growing, it will 

 produce a serious situation eventually, for it will develop 

 a condition in the scientific world in which coordination 

 of effort and a broad outlook will be much more difficult 

 than is the case now. 



This growing defect in the biological sciences can only 

 be lessened by the insistence of those in charge of advanced 

 courses in biological and physiological laboratories that 

 only those whose training is of a very wide character 

 should be allowed to take up research. It is, perhaps, 

 futile to e.xpect that such a rule will ever be enforced, 

 for in the keen competition between universities for young 

 teachers who have made some reputation for original 

 investigation there may not be too close a scrutiny of 

 the qualifications of those who offer themselves for post- 

 graduate courses. There is, further, the difficulty that 

 the heads of scientific departments are not desirous of 

 limiting the output of new knowledge from their labora- 

 tories by insisting on the wider training for the men of 

 science who are in the process of developing as students 

 of research. 



It is perhaps true, also, that there still remains a great 

 deal unobserved or unrecorded in the fields of biology, 

 physiology, and biochemistry, in the investigation of all 

 of which a broad training is' not specially required to give 

 good service ; and that, further, this condition will obtain 

 for one or two decades still. It is quite as certain, how- 

 ever, that the returns from such service will tend to 

 diminish in number and value, and, if the coming genera- 

 tion of workers is not recruited from a systematically 

 and broadly trained class of students, a period of com- 

 parative sterility may supervene. 



As it is to-day, there are few who devote themselves 

 to the direct study of the chemical and physical proper- 

 ties of the cell, the fundamental unit of living matter. 

 There are, of course, many who are concerned with the 

 morphology of the cell, and who employ in their studies 

 the methods of hardening and staining which have been 

 of very great service in revealing the structural as well 

 as the superficial chemical properties of the cell. On the 

 facts so gained views are based which deal with_ the 

 chemistry of the cell, and which are more or less widely 

 accepted^ but the results and generalisations drawn from 

 them give us but little insight into the chemical con- 

 stitution ^of the cell. We recognise in the morphologists' 

 chromatin a substance which has only in a most general 

 way an individuality, while the inclusions in the nucleus 

 and the cytoplasm, on the distinction by staining of which 

 great emphasis is laid, can only in a most superficial way 

 be classified chemically. 



The results of digestion experiments on the cell struc- 



