44 



SCIENCE. 



[Vol. XVII. No. 416 



re-actionary phenomena have been quite uniform, they have 

 proved to be far from absolutely so. 



Then as to the supposed mode of action of the lymph in 

 destroying tuberculous tissue, or scattering the bacilli, there 

 is opportunity for much difference in opinion. The doctrine 

 of specific action is losing rather than gaining ground in the 

 light of present clinical experience here and abroad. For- 

 tunately, the autopsies have been few, and pathological op- 

 portunities have been limited. So' far, there have been few- 

 lesions peculiar and striking enough to show any direct re- 

 lations of cause and effect in the use of the remedy. Many 

 observers have noted no changes whatever in tuberculous 

 joints opened by surgical operation after the lymph has done 

 its re-actionary work, while others have described degenera- 

 tive changes which may or may not have existed before the 

 inoculation treatment was commenced. The examinations 

 of lung lesions have shown equally various conditions from 

 that of limited areas of injection around decomposing tuber- 

 cular masses, as usually seen in cases under ordinary treat- 

 ment, to that of extensive infiltration of neighboring tissue. 

 The latter phenomena have been described also in con- 

 nection with tubercular diseases of the larynx, where suffo- 

 cation has been thereby threatened, and particularly in cases 

 of lupus, in which the turgidity of surrounding parts has 

 been almost the rule, and has been associated with incrusta- 

 tion of the surface. 



While such effects confirm the predictions of Professor 

 Koch regarding local re-actions, and encourage further 

 study, we have as yet made no notable progress in ultimately 

 curing tuberculosis, or in proving that the lymph acts differ- 

 ently from any other substance containing an active albu- 

 minoid substance capable of producing systemic poisoning 

 with local manifestations. Theorizing on this basis, it would 

 be legitimate to assume that any organic poison similar to 

 that which the lymph contains would attack most strongly 

 a weakened body, such as we find in tuberculous patients. 

 The parts invaded by a degenerative disease, and necessarily 

 most lacking in vitality, would be the first to be affected. 

 As a consequence, strong re-actions might easily occur in 

 the shape of increased local congestions and infiltrations, 

 with the usual attendant phenomena of an augmented gen- 

 eral febrile disturbance. From such a standpoint it may not 

 be difficult to understand how the tuberculous tissue as such 

 might be killed independently of any elective action of the 

 lymph. 



At best, we must admit that the simple destruction of the 

 diseased tissue, even if such can always be assured, is but a 

 part of a very complex process of cure for tuberculous dis- 

 ease. Something more is required than mere injections and 

 resulting re-actions. 



While we may congratulate ourselves that we have even 

 progressed thus far, we have scarcely taken more than a first 

 step. Much more difficult tasks are the safe elimination of 

 the rapid local decomposition occasioned by the lymph, and 

 the subsequent reparation of the invaded parts. Already we 

 are told that in cases of tuberculous joints and glands relief 

 can be obtained ultimately by surgical measures only. 



What becomes of the bacilli which are not directly 

 affected by the lymph treatment is a question of considera- 

 ble importance. The statement of Virchow, that when they 

 are routed they are scattered in adjoining sound tissue, is 

 doubtless backed by a careful and intelligent study of post- 

 mortem appearances. Until, however, more definite facts 

 than those already offered are given, it will be well to sus- 

 pend judgment. — Medical Record, Jan. 17, 1891. 



TREES IN LONDON. 



From a sanitary point of view, it is generally held that trees are 

 useful, though some maintain that near houses they are often 

 harmful from their shutting out sunlight. Whatever may be the 

 relative value of diilerent views put forward, observations made 

 within the last few years seem to establish the fact that within a 

 five-mile circle from Charing Cross the amount of foliage is de- 

 creasing. Many of the main roads leading out of London have 

 been planted with trees, and, largely through the influence of the 

 Metropolitan Public Gardens Association, many open spaces havs 

 been beautified by foliage. But whUe the number of trees placed 

 on public ground is increasing, both the number, and, through very 

 close lopping, the size, of trees on private ground, are decreasing ; 

 and the gains are far outbalanced by the losses. 



The losses may be grouped under two heads : — 



1. The cutting down of trees completely. This is mostly due to 

 clearances for building; and within the tive-mile circle the de- 

 struction of ti-ees in pasture-lands is small, compared with the 

 breaking-up of gardens. In many parts houses standing in from 

 one to two acres of ground are demolished for rows, or closely 

 packed semi-detached villas, and the gardens are destroyed to 

 make way for them. Recent changes in the Heme Hill district 

 are a good typical example of this. Where three years ago there 

 were around country houses grounds rich with timber and fruit 

 trees, are now roads closely built on either side, with a few square 

 yards of front that might be effectively treated with tiles and 

 small pattern "carpet bedding," but are not large enough for trees. 

 Instances of this kind might be quoted from many districts around 

 London. Again, the older roads of villas, that had some twenty- 

 five to forty feet of garden between the front door and the gate, 

 with more at the back, are in all parts little by little being bought 

 up to make streets which have their frontage flush with the pave- 

 ment, or a depth of some three to four feet, at the most, railed 

 off. The miles of plain fronted brick terraces built from seventy 

 to one hundred years ago are (probably as the leases run out) 

 being replaced by rows with their front doors leading directly 

 from the pavement. Architecturally there may be an improve- 

 ment; but the gardens, which average about thirty feet in length, 

 are lost. Front gardens are gradually disappearing from London, 

 and with them go the trees that used to make the public ways so 

 changefully pleasant from bright spring to rich tinted autumn. 



2. In districts where gardens remain, there is a large increase 

 in the cutting-down and close lopping of trees. It is difficult to 

 assign the cause for this; but whatever the explanation, the fact 

 remains that the trees, instead of being annually pruned, are sud- 

 denly lopped, till, in hundreds of cases, they are reduced to a 

 trunk and a foot or two, or a few inches, of branch-stumps. Few 

 trees grow symmetrically except when isolated, and even then 

 prevailing winds have their influence; and in towns rows of build- 

 ings have an effect similar to copses and hill contours in protec- 

 tion. And in many cases around London there may be seen trees 

 so carefully tended from year to year that they but little overhang 

 flower-beds, grow well above the pavement, and yet do not look 

 unnaturally distorted. 



Many fine elms and spreading poplars and acacias may be seen, 

 their trunks covered with ivy or other creepers, and the lower 

 branches carefully removed, so that sunlight falls on the small 

 garden, and the lower rooms have light. Ic would seem that 

 want of management while trees are young is one of the causes of 

 ignorant lopping being resorted to ; and another, that forest-trees 

 have been planted where fine-leaved and small-habit trees would 

 have been more appropriate. 



It can be easily observed that the increasing number of public 

 trees are periodically attended to, while private trees are disap- 

 pearing piecemeal, or being entirely swept away. London has, in 

 the last few years, gained in planted open places ; but the acreage 

 does not equal the small lawns, grass-plots, shrubs, and trees lost. 



A GENERAL exhibition of the Kingdom of Bohemia is to be 

 held this year at Prague, this being the centennial jubilee of the 

 first trades exhibition on the continent at Prague, in 1791. The 

 exhibition wifi last from May until the 15th of October, 1891. 



