402 



NATURE 



[February 21, 1895 



I 



its powerful ab«)rptioa, especially of the so-cilled chemical 

 rays, is to limit the intensity of respiration, and to serve as a 

 rigulator of that process " He then proceeds further, and 

 states that " the fact that only green parts of plants evolve 

 oxygen, finds its sufficient explanation in the diminution of the 

 amoont of respiration, owing to the presence of the chlorophyll 

 screen." Pringsheim thus regarded assimilation as a function 

 of the protoplasm alone, with which the chlorophyll has 

 nothing to do, except in a purely nega'ive way, by keeping ofi' 

 rays which would induce the opposite process of oxidation. 



In the same year, Pringsheim announced his discovery of a 

 body which he called Hypochlorin. This he was able to 

 demonstrate in the chlorophyll corpuscles by the aid of certain 

 reagents, notably dilute hydrochloric acid. lie regarded 

 hypochlorin as the first and most constant product of assimi- 

 lation. 



Both of Pringsheim's conclusions were sharply attacked, and 

 an extensive controversial literature soon grew up. As regards 

 the hypochlorin, it seems certain that Pringsheim was mis- 

 taken in the impirlance he attributed to this body. It has 

 been clearly shown by Arthur Mayer, and others, that hypo- 

 chlorin is not a product of assimilation, but is derived from the 

 chlorophyll itself, by the action of the reagents employed. 



The other theory, that of the screenaciion of chlorophyll, 

 has not met with much favour from physiologists, and it is clear 

 that this is, at any rate, not its only function. The inve-tiga- 

 tijns of TimlriazefT and Engelmann have proved that certain of 

 the rays absorbed by the chlorophyll (principally those in the 

 red) are just the rays mo5t active in the decomposition of carbon 

 dioxide. The chlorophyll, in fact, is not merely a screen, but 

 is also a light-trap, which catches and detains those rays which 

 are most effective in the assimilative work of the plasted. On 

 the other hand, recent investigations as 1 1 the action of light on 

 protoplasm have shown that many pigments (such as those of 

 spores and pollen-grains) are useful as screens, and have ren- 

 dered it probable that this may be a function (though not the 

 mist important one) of chlorophyll also. The discovery, by 

 Winogradsky, that certain Uicteria can assimilate carbon from 

 inorganic carbonates, without chlorophyll, and in the .absence of 

 light, is a striking confirmation of the view that the seat of 

 assimilation is the protoplasm itself, and to this extent Prings- 

 heim's opinion is completely justified. 



It would be unfair to deny considerable credit to Pringsheim 

 for the boldness and originality of his physiological theories, 

 and the energy with which he supported them. Yet it must 

 be admitted that his views on these subjects were one-sided, and 

 not characterised by the same sober judgment which distin- 

 guishes his morphological researches. Entering, in mature life, 

 upon an unaccustomed field of investigatian, he failed to add 

 greatly to his previous reputation ; and though much of his 

 physiological work is suggestive, it has not given us, as he 

 intended it should, a consistent theory of assimilation. 



Passing over some of the physiological papers of second-yy 

 importance, we come to Pringsheim's last work (l8S8), which 



treats of i' • •■■■ 'f calcareous Incrustations on water-plants. 



lie expl.i ess by the removal of carbon dioxide from 



calcium !■ during assimilation, causing the precipita- 



tion of the insoluble calcium carbonate. This theory is sup- 

 ported by the interesting observation that the incrustation only 

 takes place In the lii;Iii ; but it may be doubted whether the 

 explanation given is suliicient. 



We have not attempted to record all Pringsheim's re- 

 ■earches, but enough has perhaps been said to give some idea 

 of his life's work. 



In addition to his original investigations, Pringsheim ren. 

 dered a great service to science by means of his magnificent 

 Year-book for Scientific Botany, which shares, with the botan- 

 ical portion of the I-'rcnch ./«;;.;/<•; iles Sciences Naturelles, the 



honour of con- -..i. i, . . .-i — nrd of morphological 



and physiolo; ry to hear that, since 



the death of ; , jf litis great publica- 



tion has been undertaken by two such distinguished botanists as 

 Profs. Slra»burgcr and I'frflrr. 



By the death of l'rlng»lieim we have lost another of the 

 leaders who guided scientific botany through the period of its 

 n, growth. Very few of his grn'jration now remain ; 



tl worthy successor* behind tlicm, l)ut the work of 



1';. ..„ , in the field 'if m')r|iliolf.i;y, will not soon be 



rivalled. 



n. II. Scott. 

 NO. 132 I, VOL. 51] 



THE ANTITOXIC SERUM TREATMENT OF 



DIPHTHERlAy 

 'T'lIE subject with which we shall deal to-night, though at 

 first sight of interest to the phy-ician only, has been so 

 fully discussed in the public prims, and has been so bitterly 

 and irraiiorally opposed ontheonehand (pcihaps also unreason- 

 ably bcplauded on the othrr), that ihose who take even a 

 general interest in the public heaUh, or who ate wishful to obtain 

 some insight into the pracucal and scientific aspects of a new 

 system of treatment, may well be interested lo know something 

 of what is being so fieely discussed in the columns of our daily 

 newspapers. Beyond this, however, ni.iny lake a more personal 

 interest in a method of treatment which holds out promise of 

 help in the cure or amelioration of the symptoms and conditions 

 met with in diphtheiia. a disease which, very justly, Is looked 

 upon as one of the most dangerous with which the physician has 

 to deal. To begin with, I should like to make a frank con- 

 fession. With that conervatism which is met with even in 

 the most radical of natures, many, of whom I was one, felt 

 disposed to treat antitoxic scrum as belonging to the same group 

 of sulistances as tuberculin, around which was constnicted a 

 theory of which the labor.atory experimental basis, though ap- 

 parently fair and firm, was as yet insufficient for the support of 

 the structure of therapeutic treatment that was afterwards raised 

 upon It. 1 followed the earlier experiments on this new method 

 with great atiention ; I carefully analysed llie principles on 

 which the method was founded, and then with some misgivings 

 watched the gradual development of the treatment as applied 

 to ac ual cases of diphtheria. I was inclined to receive the 

 statistics with great reseive, as I felt that iliis new method, like 

 all new methods of treatment, might be making cures in the 

 minds of the obser\er, and not on the bodies of ihe patients. 

 Now, however, I am convinced that whatever justification my 

 incredulity may have had from the con-iderailim of previous 

 experiments, none could be claimed in connection with the 

 expc'lments that were carried out in the inves igation of this 

 sjiecial subject, .and I am ihoroughly satisfied that, although 

 the aniiioxic scrum treatment. may not come uplo the expecta- 

 tions of ail the r.ash writers on the subject — for many people 

 seem to think that it sho dd be a specific agamsi diphtheria in 

 all its stages — It promises, and this promise has in pait been 

 rdcemed, to dimmish the diphtheria case mortality in a very 

 remarkable manner. 



What is Diphlheria ? 

 It is primnrilyan inflammation of the mucous membrane (the 

 moist skin) of the tonsils, of the soft p.ilaie, of the upper part 

 of the gullet, and of the upjier part of the windpipe. During 

 the course of this Inflammation, which appears to be set up by the 

 aciion of a special bacillgs. there are usually thrown out some of 

 the fluid elements of the blood and some of die white cells that 

 float in the blood ; these coagulate and lorm asoft lout;hish layer 

 or film which oflcrs an excellent food and resiing place for this 

 bacillus, which under such favourable conditions secreles or 

 manufactures a most virulent poison. This poison is rapidly 

 absorbed into the blood and is carried to various parts of the 

 bDdy ; its effects are evident at first only os the nervous 

 system, but afterwards on the muscles. 



The liacilius of J diphlheria. 

 First as to the bacdlus. In 1875 Klebs described a short 

 bacillus which he found on Ihe suilace of the greyish leather- 

 like diphtheriuc false membrane or film. Following up these 

 observations, I.oefller traced a definite etiological lelatlon- 

 shlp between this bacillus and diph herla. First he obtained 

 pure cultures of the bacillus by growing it on .solidified 

 blood scrum, or on a mixture of three pans of blood sciuni and 

 one part of neutralised beef bouillon coii aining cxiraci of beef, 

 I per cent, of peptone, 05 per ccni. ol common salt, and 1 per 

 cent, of grape sugar. This organism may be readily detached 

 from the surface of the false membrane by pressing 

 fiimly but gently with a liille bit of cotton wadding twisted 

 round the end o( an iron wire or nn ordinary penholder. 

 When stained and examined under the mi roscnpe Ihe 

 diphtheria bacilli arc fout.d 10 be .small rods liom 3 to 6 ^ (i m 

 = ..:,.'. ,...'h of an inch) inlergih, fairly plun p, siiaighi, i>r slightly 

 curved, i-oii etimcs wedgc-sha]ie<l or poinerl, but usually some- 

 what enlarged and rounded at the ends, where also in stained 



1 A lerlurc .delivered al the Royal Intlilulion, on Friday. February 8, 

 by Dr. G. .Sinn Woodhead. 



