June 1, 1899.] 



KNOWLEDGE, 



125 



But with enzymes the case is very different. Appar- 

 ently their power of influencing is Ulimitable. They do 

 not change themselves and so they can continue to exert 

 the influence that is peculiar to themselves for an 

 indefinite time. There is no point of stable equilibrium 

 in this relationship. Enzymes stand in a position of 

 great interest nowadays when the search among the 

 beginnings of life is so intense, and when the eifort to 

 prove or disprove spontaneous generation — the origin of 

 life from the non-living — is so keenly maintained by 

 chemists and biologists, for in one instance certainly 

 where very careful and exact study has been made of an 

 enzyme it is suggested that the substance stands midway 

 between the organic and the inorganic, that it is the 

 stepping stone across the gulf which has hitherto divided 

 the great world of the living from that which has never 

 known life. 



Thus it appears that a simple consideration of the 

 change of colour in a raw apple may lead back to the most 

 far-reaching questions, and involve problems which touch 

 closely the most incomprehensible matters of life and 

 being. 



The particular enzyme — malase — -which is found in the 

 cells of an apple effects its work by causing some of the 

 oxygen of the air to be transferred from the air to a 

 substance also found within the cells — the tannin — and it 

 is suggested that it serves, in some sort of a way, as a 

 carrier. And the result of its influence on tannin is that 

 the nature of the tannin is altered, and dark-coloured 

 substances, compounds of oxygen, are formed which dye 

 the walls, first pinkish, then a dull red, and finally a dirty- 

 brown. It is obvious that though the malase is probably 

 always present in the cells, it cannot exert its influence 

 to any purpose while the apple is whole, and surrounded 

 by a firm clear skin, for the air cannot obtain admission 

 until the peel is removed or the apple cut through, and 

 hence there is no free oxygen to work with. But when 

 the cells have been exposed the air enters, the malase 

 transfers, in some mysterious way, the oxygen, the tannin 

 is changed in nature, and the cells are dyed with the 

 products. It is by no means certain that the malase and 

 the tannin must be side by side in the same cells for this 

 effect to take place. Lindet is inclined to think they are 

 not, and that the malase exerts its influence for some 

 distance, but this is a question which calls for further 

 research before any more definite answer can be given. 



The name oxydases has been suggested by Weigert for 

 the enzymes which are engaged in the process of the 

 transference of oxygen, a name which has the advantage 

 of giving a clue to their function. This method of 

 oxidation is quite distinct from the two other more familiar 

 methods by which oxidation may be directly brought about : 

 these two other ways being, first, the life processes in 

 bacteria, where oxidation is an outcome of then- vitality ; 

 and, secondly, the simple chemical fixation of oxygen, such 

 as when sulphur dioxide ( SO-,) becomes converted into the 

 trioxide (SO,) in the presence of oxygen. 



But, as Prof. Lafar points out, the whole subject of 

 oxydases, i.e., of the oxidising enzymes, is yet in its 

 infancy, but sufficient is known to give grounds for hope 

 that it may prove to be a fruitful source of explanation in 

 many instances where hitherto much has been perplexing, 

 and that it may serve to throw light into dark places. The 

 rapid discoloration of fresh vegetable juices is a case in 

 point. These have always proved a source of difficulty to 

 the botanist, and no really thorough comprehension of the 

 subject has been arrived at, but now the recognition of 

 these enzymes in plants is a help out of the maze. For 

 now oxydases have been directly proved to exist in many 



fruits, such as pears, chestnuts, and quinces, and also in 

 various vegetables, such as carrots, and potatoes, and beet, 

 and the inner tissues of all these, as common experience 

 shows, have a tendency to become discoloured when exposed 

 to the air. 



Malase and the other plant enzymes can be isolated by 

 squeezing out the juice of the plant and mixing it with 

 alcohol, when a precipitate is thrown down. This pre- 

 cipitate is then dissolved in water and filtered, and if again 

 alcohol is added to the result a new precipitate will appear, 

 which is the enzyme of the plant juice in question, and 

 which is thus free for further examination and treatment. 



It is not known as yet how many kinds of oxydases there 

 are, but several of them are known to be the cause of 

 familiar phenomena. For instance, it is only since 189.j 

 that it has been effectively shown that the darkening of 

 colour sometimes seen in white wines — the " browning 

 of wines ''—is due to the action of an enzyme which acts 

 in the same way as malase in the apple, and its discovery 

 has led to further knowledge as to the means of prevention 

 of this trouble in viticulture. 



Then, again, with regard to the darkening in colour of 

 mushrooms and allied fungi when broken and exposed to the 

 air, this was in 1895 found to be due to an oxydase which 

 brought about oxidation in a similar way ; and only quite 

 recently in ripe olives another has been found which brings 

 about spontaneous decomposition, but is not yet sufficiently 

 studied to allow of much definite knowledge. 



The laccase already mentioned earlier is an enzyme 

 which plays the all-important part in the hardening and 

 darkening of the plant juices which are the basis of the 

 celebrated Japanese lacquer. 



ON THE TREATMENT AND UTILIZATION OF 

 ANTHROPOLOGICAL DATA. 



By Arthur Thomson-, m.a., m.b. 

 III.— RACIAL PROPORTIONS. 



M 



ANY interesting facts relating to the various 

 proportions of the body in different races may 

 be culled from the vast number of measurements 

 which have been made. Unfortunately, though 

 the material at our disposal is very considerable, 

 so varied have been the different methods employed by 

 those responsible for the measurements that it becomes a 

 matter of endless labour to form any generalisations from 

 the statistics at hand. It has ever been the delight of the 

 physical anthropologist to improve on the methods of his 

 predecessor, and this improvement generally takes the 

 form of some addition to the long list of measurements 

 hitherto taken. In many cases these improvements are 

 but an additional burden to the masses of figures already 

 sufficiently numerous and perplexing. What is wanted, is 

 not an increase, but a reduction in the number of the 

 measurements deemed necessary. 



It seems to us that the value of the dilTerent methods 

 employed may be tested in a very simple way. Confining 

 our remarks, for the time being, to the question of bodily 

 proportions, it is only reasonable to suppose that the data 

 supplied should be such as to enable a sculptor or modeller 

 to apportion correctly the various members of the body. 

 Subjected to such a test, most of the systems adopted by 

 anthropologists break down miserably. Let anyone try it 

 for himself. Taking the body height as equal one thousand, 

 the various measurements of the limbs and trunk may be 

 worked out in this proportion. If now an attempt is made 

 to plot out on paper ruled in squares of centimetres the 



