March 5, 1885] 



NA TURE 



425 



were made dining the month of June show conclusively thai, 

 previously to the development of Bacillus urea, the chemical 

 composition of the urine remained practically unchanged ; but 

 with the appearance of micro-organisms, a diminution of organic 

 carbon and a transference of nitrogen fron the organic to the 

 ammonia column immediately began. As regards rapidity, this 

 change marched pari passu with the density of p ipulation, and 

 reached its maximum about the 12th day; fir during the three 

 days (nth to 14th) nearly 10 per cent, of carbon disappeared, 

 whilst more than 85 per cent, of the organic nitrogen became 

 ammonia. After the 14th day the rate of change became much 

 slower, on the iS h day the bacilli were mostly either dead or 

 motionless whilst on and after the 23rd day no more moving 

 bacilli was seen. Altogether the quantity of carbon c inverted 

 into carbonic anhydride, after allowing for concentration of 

 the liquid by evaporation, amounted to 597 04 parts per 

 IOO.OCO of liquid, or 63-3 per cent, of the total quantity ; 

 whilst the quantity of organic nitrogen converted into 

 ammonia was 546'ia parts per 100,000, or 5o'6 per cent. 

 of the whole. These proportions show that all the organic 

 nitrogen contained in the urea was nit converted into 

 ammonia. It no doubt escaped as free nitrogen, in accordance 

 with Frank Hatton's observation. In the original urine the 

 proportion of organic carbon to organic nitrogen was as 1 : 1 '15, 

 whilst, after the action of the bacilli, it was 1 :o'62. Prof. 

 Burdon Sanderson said that the main difficulty met with in study- 

 ing the effects of micro-organisms arose from the fact that it was 

 always difficult and often impossible to distinguish between 

 different organisms. Chemists might naturally turn to biologists 

 for aid in the matter, but biologists must admit the existence of 

 this difficulty. We are fully acquainted with the life history of 

 only one pathogenic organism — Anthrax bacillus : of this, 

 thanks to Koch, we know, however, a great deal. The method 

 followed by biologists in studying pathogenic forms was, in the 

 first instance, to prepare a pure cultivation of the organism, and 

 then to obtain the proof that the organism produces its proper 

 effect when transferred to a living animal. The morphological 

 relations of bacteria with plants could not be questioned, but he 

 thought it was really of little consequence for practical purposes 

 whether ferment organisms were regarded as animals or plants ; 

 what we want to know is, what are the conditions under which 

 an organism is produced, and its life history. He was in the 

 habit of calling them microphytes, as being a neutral term. — 

 Prof. Kay Lankester was astonished at the definite way in which 

 Prof. Frankland had classed the ferment organisms with animals. 

 Naturalists were led to regard them as plants from examining 

 their relations to oth;r organisms. He agreed with Prof. 

 Sanderson that "microphyte" was a good name for them, 

 although not precisely for the same reason, but because it really 

 meant a little plant. He stated that it was held hitherto that a 

 micrococcus induced the amnionic change in urine, and not a 

 bacillus as figured by the lecturer. For the purpose of chemical 

 investigation, it was essential to have a pure cultivation. It 

 was curious that the nitrifying organism had not been isolated ; 

 it- presence had only been inferred, and it had never been 

 satisfactorily separated and identified, although inconclusive 

 statements and observations purporting to inform us as to the 

 form of that organism had been published. — Dr. Brunton said 

 that it was highly probable that the symptoms occurring in 

 certain diseases were due to poisons formed by the action of 

 organisms and not directly to the organisms themselves. This 

 was not improbably the case in cholera. Micro-organisms may 

 even produce substances fatal to themselves, e.g. , phenyl com- 

 pounds. This is also the case with higher organisms, the 

 retention of the urine in man being often attended with fatal 

 results. Although cholera was very probably due to the presence 

 of low organisms, the symptoms were so very like those pro- 

 duced by certain poisons, that it was very difficult to diagnose 

 cases of poisoning by arsenic from cholera cases. The cholera 

 poison was probably of an alkaloidal character and related to 

 the ptomaines. Pepsin converted albuminoids into peptones, 

 but it was important to note that Brieger had observed that 

 sometimes an alkaloid having an action similar to curare was 

 formed during peptic digestion, and an alkaloid having a 

 similar action had been obtained from human urine. These 

 facts rendered it probable that alkaloids might be formed in the 

 intestinal canal and absorbed into the general circulation. Prof. 

 M. Foster said that the question whether the micro-organisms in 

 question were plants or animals was to him a matter of in- 

 difference compared to the question — what was the exact nature 



of the action by which the organism effected the chemical change ? 

 He desired to point out that in certain cases, as in the amnionic 

 conversion of urea, the same change, in this case the conversion 

 of urea into ammonium carbonate, was effected, on the one hand, 

 by a micro organism, a micrococcus or bacillus, and on the other 

 hand by an unorganised ferment. His friend Mr. Sheridan Lea 

 informed him that he had evidence of both these causes of 

 alnmi mic conversion of urea. Now, was the action in both cases 

 the same ? The idea had naturally occurred that the organism 

 produced its effect by producing an organised ferment. But all 

 attempts to prove the production of such a secretion, so to speak, 

 of a ferment had failed If such a ferment were produced, it 

 was destroyed or disappeared during its action, whereas ordinary 

 unorganised ferments such as pepsin, &c, were not destroyed at 

 all during their activity, or were destroyed very slowly. On the 

 whole, the probability was that the micro-organism and the 

 unorganised ferment produced the same result in different ways ; 

 ought not the difference to offer the key for solving the problem ? 

 He further desired to remind the Fellows that actions similar to 

 those of these micro-organisms were continually being carried on 

 by the constituent elements of man and other macro-organisms, 

 and would wish, in illustration, to call their attention to the act 

 of secretion by a secreting cell, such as the \ ancrealic cell. We 

 had evidence that certain constituents of pancreatic juice existed 

 in the cell, not in the form in which they appear in the juice 

 itself, but in an anterior, more complex condition. Thus tryp.-in 

 occurs in the pancreatic cell not as trypsin but as trypsinogen. 

 Now this trypsinogen, and also probably other "mothers "of 

 the constituent of the juice, exist in the protoplasm of the cell as 

 discrete granules, lodged in the meshes of the protoplasm, separated 

 from the protoplasm by films of fluid. Yet the protoplasm, 

 stirred by some nervous impulse, is able to produce a change in 

 these granules, so that they are discharged to form the secretion. 

 How does the protoplasm work upon these granules ? Does it 

 discharge something into the fluid of its meshes, which something 

 acts upon the granules ? or does it work upon the granule through 

 the film of fluid surrounding the granule, by something which is 

 a sort of " action at a distance " ? The action, then, in this case is 

 very comparable to the action of the micro-organisms in question. 

 It is for the chemists to throw light on the exact nature of the 

 changes produced, and, when this is done, we may hope to learn 

 how the change is brought about ; but not until this is done. — 

 Mr. Thistelton Dyer said that from the botanist's point of view 

 he was struck with the universality of fermentative changes. 

 Though they were so predominant a feature in the life of the 

 lower plants, this was only an extreme manifestation of what, 

 perhaps, all plants were capable of, if the conditions demanded 

 it. Thus Pa teur, following up an experiment of Berard's, 

 found that a rhubarb leaf in an atmosphere of carbon dioxide 

 yielded, after 48 hours, though apparently unchanged, small 

 quantities of alcoh il. The breaking up of molecules of large 

 thermic equivalent into those of less, supplies the energy needed 

 for the continued life of the ti-sues, and is the raison delre of the 

 process. But plants also set up fermentative changes external to 

 themselves, as it were incidentally and without any obvious 

 benefit. The investigation of Beyerinck on the production of gum 

 by plants yielded most remarkable results. It is due to a disease 

 which is highly contagious, and which is caused by a fungus 

 (Coryneum). This produces a ferment which changes the cell- 

 walls into gum. But what is most remarkable is that even after 

 the di:.appearance of the fungus which initiated the changes, the 

 the cells of the host plant take on a morbid habit of growth, and 

 themselves continue the production of the ferment and therefore 

 of gum to their own hurt. The problem is here of the most 

 complicated kind. The series is ended by cases such as that of 

 Withania coagulans (and many others are now known), where 

 plants throw off, as bye-products of their metabolism, ferments 

 as effective as rennet, without deriving any perceptible advantage 

 from their possession. That plants use in working up their 

 reserve-proteid proteolytic ferments just as animals do, cannot be 

 doubted. But even these they occasionally, as in the Papaw, 

 produce in utter disproportion to their own possible require- 

 ment-. Mr. Warrington said with regard to the difference 

 between animals and plants, he thought the fact had been 

 somewhat overlooked that plants are able to obtain their 

 nitrogen from such simple compounds as ammonia and 

 nitrates, whereas animals appear to require to have the 

 nitrogen presented to them in an albumenoid form. As to 

 the nature of the nitrifying organism, Miintz and Schlosing 

 claim to have isolated it and have described it. A friend who 



