i 



September 2, 1915] 



NATURE 



23 



ease of activity (amoeboid motion?). Later, when 

 greater amount of the substance has been taken in, 

 the paralysing efTect gets the upper hand. With 

 alcohol the same experience is well knmvn. 



In following this point we are led to think of the 

 remarkable influence of a sojourn in high mountain 

 regions, on metabolism, on sleep, and on the state of 

 the mind. The cause is entirely unknown. It has 

 been proved that these phenomena are not due to the 

 height as such, for in balloons they do not occur, nor 

 are they found in high mountain regions, but when 

 examining where they are observed, we find that it is 

 in the neighbourhood of coniferous woods. So we 

 are inclined to think that it is due to the stimulating 

 efTect of the odour of resin (turpentines, etc.) on the 

 nerve-cells. 



Prof. Sherrington and Miss Sowton, in their 

 studies on the dosage of the mammalian heart by 

 chloroform, found that, especially with greater 

 amounts of the drug, it was usual for the first effect 

 of the administration to be a distinct though slight 

 increase in amplitude of the contractions. After 

 cessation of the administration of the drug in moderate 

 dose, it was not unusual before the recovery of the 

 beat for the heart to pass over for a short time into a 

 condition of super-activity. These phenomena suggest 

 an irritative excitatory efTect of small doses of the 

 substance on muscle or nerve-fibres (or both) of the 

 heart. These results agree with those previously 

 obtained by Prof. A. D. Waller in his experiments 

 with the isolated nerve. 



There are experiments also with other organs which 

 may be considered in the same light. Thus Prof. J. 

 Loeb discovered that substances dissolving fat have 

 the power of rendering possible the parthenogenetic 

 development of eggs. Now we may imagine, with 

 Loeb, that the substance dissolves in a lipoid of the 

 outer layer of the egg, thus giving rise to the forma- 

 tion of a fertilising membrane. We think we may 

 safely go one step further and assume that it is owing 

 to the weakening of the membrane that the movement 

 of the protoplasm underlying every cell division mani- 

 fests itself. This view is confirmed by the observa- 

 tion of Prof. R. S. Lillie, who saw also that by a 

 short transitory raising of the temperature in the 

 eggs of starfishes a typical fertilising membrane may 

 be formed, which formation is followed by the develop- 

 ment of part of the eggs into larvae. J. Loeb was 

 able to confirm this for Medusae. 



After consideration of the foregoing facts and sug- 

 gestions, we were inclined to think that the stimulating 

 effect of traces of substances which dissolve fat on 

 the activity of cells is a widespread phenomenon. 

 Hence we have investigated whether this influence 

 might also be seen in plant-cells. To do so, we chose 

 the germination of seeds, a process in which a con- 

 siderable division and growth of cells manifests itself. 

 The seeds we chose were grains of wheat, and for 

 the fat-solvent we took chloroform. With chloroform, 

 I part to 100,000, an important acceleration in the 

 germination was observed ; chloroform i to looo, on 

 the contrary, impaired the germination, evidently 

 because a second factor made itself felt, viz. paralysis 

 of the protoplasm. Later I heard that in practice the 

 growth of snowdrops is promoted by ether. In recent 

 times Chiari succeeded in forcing blossoms to a con- 

 siderable extent by ether-vapour, and Mansfield the 

 germination of pumpkin-seeds by vapour of alcohol 

 and ether. 



Hence it is clear that the observations on phago- 

 cytosis deserve our attention on general grounds as 

 well as special. We do not at all mean to say that 

 all substances dissolving fat have the same effect on. 

 cells of all kinds ; far from" it. I would emphasise 



NO. 2392, VOL. 96] 



that, in order to be brief and to avoid complexity of 

 detail, I have here presented the matter somewhat 

 simpler than it really is. Nor have all the suggestions 

 here made towards explaining facts regarding other 

 cells than phagocytes been actually proved. Without 

 hypothesis, science cannot progress. Fortunately we 

 need not stay in error for long, for we can always 

 appeal to the supreme judge, experiment. 



This account of results and views, the fruit of some 

 years' work with several collaborators (Hekma, de 

 Haan, etc.),=' being of necessity incomplete, I have 

 attempted to select what may specially interest the 

 general scientific reader. 



We are continuing our study of the biology of 

 phagocytes, and each day we become more convinced 

 of their excellence as a simple object, for the study 

 of problems of a general biochemical nature, and for 

 some of practical interest as well. 



H. J. Hamburger. 



IRELAND'S INDUSTRIAL OPPOR- 

 TUNITIES. 



A LECTURE delivered in April last before the In- 

 ■^"^ surance Institute of Ireland by Mr. George 

 Fletcher, the assistant secretary of technical instruc- 

 tion, and recently issued in pamphlet form, deserves 

 the serious attention of all well-wishers of Ireland. 

 We have in Ireland a population little more than half 

 of what it w^as in 1841, and which is now annually 

 depleted by emigration to such an extent that any 

 increase in its population is well-nigh impossible. 



It is obviously, therefore, of the highest possible 

 importance to the well-being, not merely of Ireland, 

 but also of the kingdom generally, that means should 

 be taken to ensure the utmost development alike in 

 agriculture as in manufactured products, since it is 

 now clearly realised that it is only by a combination 

 of both that the well-being of Ireland can be firmly 

 established. 



The Department of Agriculture and Technical In- 

 struction established in 1899, mainly through the 

 strenuous efforts of Sir Horace Plunket, the first vice- 

 president, has done much for the promotion of agri- 

 culture and its products and of manufacturing industry. 

 Improved methods have been introduced into farming, 

 fishery, and industrial operations, especially in the 

 latter case by the encouragement of cottage industries, 

 with a view to find employment for the rural popula- 

 tion in times and seasons not devoted to agricultural 

 work, and with a view also to add to the interest of 

 an otherwise monotonous life. 



Large sums have been spent as a result of local and 

 Governmental effort in the promotion of technical 

 education, with the result that now practically all over 

 Ireland facilities exist for the due training of the 

 workers engaged in agricultural and industrial pur- 

 suits. At the same time, the Department has per- 

 sistently urged the necessity; if technical training is 

 to be of any real value, of a better and more pervading 

 system of elementary and secondary education upon 

 which to found it, and also for the reason that it is 

 desirable to widen by means of a sound general educa- 

 tion the mental horizon of the people. 



Believing that no jjermanent good can 6e ensured 

 except by the co-operation of the people themselves, it 

 has been the aim of the Department to encourage the 

 formation of associations of farmers and manufac- 

 turers, so as to secure a sense of solidarity and of 

 common effort. 



2 A full account of the researches as far as the year igii can be found in 

 my monograph " PhyMkalisch chemische Unteriuchungen uber Phaeozyten. 

 Ihre Be entung vom allgenKein biologiscben und pathologi«hen Gesichts- 

 punkt." (Wie>baden : J. F. Bergmann, 191a.) 



