15 111.-Contributions to the €&tory of Pwtrefdon. Part I. By c. T. KENGZETT. IT appears t o be now well established that matters of animal and veget'able origin present no inherent tendency to pass into a state of putrefactive decomposition. In other words putrefaction is the ex-pression by which is indicated a number of specific changes induced in certain bodies by causes extraneous to the substances themselves. For the greater part of existing knowledge of this subject we are indebted to the researches of Pasteur (Conzpt. rend. 56,1189 ; Jak-esb. ,f. Chem. 1863 579) who in 1863 defined putrefaction as a fermenta-tive process induced and sustained by animal ferments of the genus Fibs-io. This definition received confirmation from Traube and Gscheidlen (DingZ.polyt. J. 222 352 ; Chesn. SOC. J . [2] 12 997), among others in lS74 and still more recently from the very interest-ing and well known experiments of ProEessor Lister. It has been subst,antiated then that just as any kind of fermenta-tion is an instance of a biological reaction manifesting itself as the result of a special force residing in organisms or in other words as " fermentation is essentially a correlative phenomenon of a vital act, beginning and ending with it,"* so also is putrefaction such another instance of a biological reaction or such another correlative plieno-menon of a vital act. Both in fermentation proper and in putrefaction there is organisation development and multiplication of the living agents. It is probable also that although certain kinds of fermentation seem to depend upon specific unvarying organisms yet in a modified form fermentattion can also be induced in the same medium by different fer-ments or organisms just as a number of hydrating agents may cause the same order of decomposition in certain chemical substances the only difference being in the specific nature of the acting agents and the resulting products or some of them.Pasteur recognises two kinds of putrefaction viz. one in which the ferment (as for instance the butyric ferment) produces the change without the aid of oxygen and that in which oxygen is also essential in promoting such change. But however this may be it is certain that mere temporary expo-sure to the air is sufficient in the vast majority of instances to intro-duce into any putrescible solution the agencies of putrefactive change.J(; See Schiitzenbei-ger's Work on Fermentation (Eing and Co.) p. 39 16 KINGZETT COSTRIBUTIOKS TO THE Under this view of .things when a putrescihle solution is exposed to the air there forms on the surface a film of bacteria mucors and mucitlines which are supposed to exclude and absorb oxygen pre-venting i t from penetrating into fhe liquid. Under the film in the liquid vibriones multiply and split up the albuminous substances into simpler products while the bacteria and the miicors excite the slow combustion of these latter into ultimate products. This is If. Pasteur’s view of the changes constituting putrefaction and it should be parti-cularly observed that vibriones cannot endure the presence of oxygen ; their function is the institution of initial change which is completed by the bact.eria and the muc0rs.X ‘‘ It follows from what has been said that contact of air is by no means necessary for the development of putrefaction.On the con-tsary if the oxygen dissolved in a putrescible liquid was not a t once removed by the action of special organisms putrefaction would not take place ; the oxygen would destroy the vibrios which would try to develop at first.”? As regards the first products of putretactive change so far as is known they resemble those or a t least are identical in some measure with those obtained by subjectiug albumino‘ids to chemical decompo-sition by hydrating agents such as dilute sulphuric acid and baryta-wat,er. This kind of decomposition has been specially studied by Schutzenberger.The ultimate products of putrefactive change would seem to result from the oxidation of the primary products and from certain ill-defined secondary influences. Under these circumstances one would naturally expect that a sub-stance allowed to undergo putrid fermentation without oxidation, would more readily undergo chemical oxidation than the original integral mass and hence that the oxygen-absorbing capacity of a sub-stance would progress increasingly with such putrefactive decomposi-tion. It thus occurred to me some time ago that advantage might be taken of this inference to compare quantitatively the prophylactic energies of various substances by determining the oxygen-absorbing capacities of organic solutions or mixtures from time to time as they passed into putrefaction and comparing these with the oxygen capacities of similar solutions protected during the same periods by so-called antiseptics.Accordingly after considerable unavoidable delay I commenced the experiments some of which I have now the honour of submitting to the Chemical Society. * Compt. rend. June 1863 and Schijtzenberger on Fermentation (King and Co.), f- Page 219 of Schutzenberger’s treatise. pp. 209-227 HISTORY OF PUTREFACTION. 17 I have made a large number of experiments of this kind but do not propose to publish the results on this occasion. It may be remarked that the investigation presents great difficulties and i t is only from a very large series of observations that any sound inference can be made.The problem would lose nearly all its difficulties if all anti-septics exercised the same kind of influence sa-j- for instance the strengthening of the combinations to break down which constitutes the function' of vibriones. But this is not the case and moreover most of the antiseptic substances tested react upon the potassic per-manganate in a chemical manner of their own. Hence the difficulties of the investigation which I am carrying on. Some of the experi-ments which I have made however seem to have an important bearing upon what Dr. Tidy describes as the " oxygen process " of water analysis and T shall only preface the description of these ex-periments by stating that I was not led to the subject by any spirit of criticism much less of hostile criticism but purely incidentally.There is a wide-spread opinion that in the putrid state a substance is capable of absorbing much more oxygen or to put i t in another way of decomposing much more potassic permanganate than in the fresh state and indeed it appears to me that the " oxygen process " of water analysis as recently described by Tidy (Chew. Soc. J., 194 80 specially) largely depends upon this assumption for he ob-serves " At anjr rate it undoubtedly furnishes us with exact informa-tion as to the relative quantities of putrescent and easily oxidisable matter and of non-putrescent or less easily oxidisable matters present in the water.'' I shall show presently that this is not clear and it appears to me that; the oxygen process is liable to mislead chemists in interpreting their results if we are to believe that the more per-nicious organic matters are those which are in a putrescent condition.For it will be seen that a water may contain a t one time organic matters in a non-putrescent condition and that when these same matters shall have become pernicious the water will absorb far less oxygen than originally ! Experiment 1 (Azcgust 14th 1879).-A dilute solution of white of egg was made filtered from membranous matter and found to contain 1.588 per cent. albumin dried a t 100" C. Of this I took 5 c.c. added 90 C.C. of distilled water then 5 C.C. of dilute sulphuric acid (1 3), and lastly 20 C.C. of a standard solution of potassic permanganate (1 C.C. = -001334 gram oxygen).The mixture was allowed to stand one hour, and the unused permanganate was then determined by estimating its equivalent of iodine with a standard solution of eodic thiosulphate in the usual way (1 C.C. = -000667 gram oxygen or f C.C. standard per-manganate). Ti1 this manner I ascertained that the albumin operated upon used VOL. XXXVII. 18 KINGZETT CONTRIBUTIONS TO THE up during the hour 6 C.C. RMnO4=*008004 gram oxygen. This then I call the " initial oxygen-absorbing capacity." 45 C.C. of the same albumin solution was now placed in a stoppered bottle of about 100 C.C. capacity and a t the periods shown below the oxygen-absorb-ing capacity was again determined upon different port'ions but under exactly iden tical conditions with the results also shown.Oxygen capacity After After After at start. 24 hours. 120 hours. 1104 hours. After After After 1176 hours. 1 4 0 hours. 1534 hours. 0 * 0 06203 1 0.0058696 0.0054694 The solution began to stink after about 150 hours' standing and henceforth i t grew worse being ultimately of a glutinous stringy con-sistence and smelling strongly of cheese having entireIy lost its purely putrefactive odour. Eqm+t?mt 2 (Augztst 27 1S79).-A pound of raw beefstea,k was digested with about 400 C.C. of water a t 50" C. for two hours filtered after cooling and allowed to stand over night. Next! morning it was already slightly pntrid t o the smell. The initial oxFgen-absorbing capacity was determined using Fi C.C. of the extract diluted with 100 C.C. of water adding 5 C.C. of 1 3 H2S04 and 20 C.C.KMn04 solution. It absorbed 0*00867l gram oxygen. 60 C.C. of the extract was now placed in a stoppered bottle of 80 C.C. capacity and another similar bottle was entirely filled with the extract, so that it was not exposed to the air. The oxygen capacities of these two solutions were then determined a t the periods and with the results here following :-0.008004 0.0086 71 0.0076038 0.00667 A. Partially filled Bottle. Initial. 24 hours. '72 hours. 144 hours. 168 hours. 0.008671 0.0089378 0.0081374 0-0081374 0*008004 0.007337 - 0-006003 0-005336 0*0050692 0.0042688 648 hours. 672 hours. 792 hours. 840 hours. 1128 hours. 1224 hours. B. Efitirelyfilled Bottle. 0-0086 71 - - - 0.0089378 0*011%39 0.0037358 0.0034684 0-0034684 - -InitiaI.24 hours. 72 hours. 144 hours. 168 hotirs. 648 hours. 672 hours. 792 hours. 840 hours. 1128 hours. 1224 hours. After 48 hours both bottles were maintained at a temperature of 49O for three hours to hasten putrefaction HISTORY OF PUTREFACTION. 19 I n A the putrefactive odour was unbearable before heating t o this temperature but curiously enough when examined after 72 hours i t smelt quite sweet. It again stank at the 14.4 hours’ examination and the odour grew worse and worse a deposit* occurring gradually and much gas being evolved on agitation. Finally the solution became quite colourless or nearly so all the colour being in the deposit. At the 1128 hours’ examination it was perfectly sweet to smell emitting only a meaty odour ; so also a t 1224 hours. B when first opened after 168 hours was found to be terribly putrid and of course after this date and up to 648 hours it was i n contact with 5 C.C.of air and after each examination the quantity of a i r was increased by 5 C.C. (the mensnPe of fluid removed). As regards appearances and odour it followed the course of A so far as observed. Experiment 3 (October 1 1879).-In this experiment I took a beef-steak in which the process of putrefaction had already commenced ; a piece of fresh herring in a similar condition and the piece of a cab-bage and made an infusion a t 40° cooled and filtered it. A small stoppered bottle was then entirely filled with a quantity of this s o h -tion and a further quantity of tbe same solution was placed in a corked bottle containing about 400 C.C.of air. The method of pro-ceeding was as in the last experiment. A. Extract in f d l Bottle. Initial oxygen 0.005 8696 - 0,0034684 0.00314824 0.00490912 0.00410872 0.004005 0*0041385 0.0041408 capacity. After 24 hours. After 336 hours. After 432 hours. After 840 hours After 1032 hours. After 1128 hours. After 1224 hours. After 1’7’76 hours. B. Extract exposed to Air from the .&a?%. Initial oxygen capacity. After 24 hours. After 336 hours. After 432 hours. 0*0058696 -0050692 0.0034684 0-00314824 0.00442888 0.0034684 After 84Q hours. After 1032 hours. On October 13 that is to say after 336 hours and when putrefaction was in full work 22.5 C.C. of the extract in Bottle A was pIaced in contact with 55 C.C. of air over mercury. After five days the volume f This deposit which occurred in dl the fluids which were allowed ho pass into putrefaction was of a silty nature and in no way interfered with the determina-tion of the oxygen-capacities since by agitation of the fluids it could be equally disseminated throughout the mass.This was proved by making (in the majority of instances) duplicate experiments which always yielded the same results. c 20 KINGZETT CONTRIBUTIOKS TO THE of gas in tube measured 59 C.C. A little caustic potash was now intro-duced and this absorbed 4 C.C. of gas leaving therefore the original volume unabsorbed. I do not attach much importance to this experi-ment; i t was quite of a preliminary nature and perhaps after all, oxygen had been absorbed from the air and an equal volume of other gas (hydrogen or nitrogen) unabsorbable by potash set free.Be this, however as it may it would seem from the comparative experiments, A and B that this one instance of putrefaction in no way depended upon the contact of air per se and a a y indeed proceed independently of it. The putzefaction in A and B proceeded rapidly the solutions keep-ing their red colour which even seemed to intensify for Bome time. On examination at the 336 hours both were horrible to smell and had largely deposited ; both evolved much gas on agitation. The appear-ance was much the same after 432 hours. Later on the red colour of the solution disappeared the deposit simultaneously increasing ; the odour too changed from the recent putrefactive to a stale butyric odour.After 1032 hours A had not lost this latter smell altogether, but B had and cmitted only the smell of some compound ammonia. Z y e T i m e n t 4 (November 3 1879).-Four or five pounds of raw lean beef was minced and macerated in pure water a t about 40". The extract contained 3 per cent. (?) solid matter dry a t 100". A. 200 C.C. of this cxtract was placed in a stoppered bottle of about '250 C.C. capacity. B. 200 C.C. of the same extracf was placed in a stoppered bottle of this exact capacity. C. 50 was exposed to 47.5 C.C. of air over mercurr. Initial oxygen capacity of After Aftrr Af tcr After Aftw 5 c c. 96 hours. 192 hours. 278 hours. 37'4 hours. 926 hours. A . moo73959 -006942 -0064614 *00631455 ~006942 -0064355% C. .0073959 -00643552 B.*0073059 - - -006942 -007743~ -0068m6 Volume of gas in air-tube = 44.5 C.C. -0071289 A and B both began to stink after 48 hours from start and both grew increasingly worse and made a considerable whitish deposit. Now postponing for the moment the consideration of these results in regard to the phenomenon of putrefaction they seem to reflect as I have already said upon a probable source of error in the rjxygen pro-cess of water analysis. During the discussion upon Dr. Tidj 's valuable paper I pointed out that pernianganate of potash according to his own * After this examiiiation a quantity of this extract was placed in a bottle of its precise measure and a t the 926 hours' stage the oxygen-capncity as found to bc -0075'712 HISTORY OF PUTREFACTIO~ 21 results (this Journal 1879 1 78) seems to have little influence upon gelatin in a fresh state; and since gelatin is one of a class of bodies liable to putrefactive changes and hence liable to give rise to perni-cious products it appeared to me that the oxygen process was liable to overlook certain albumino'ids which was a serious objection.I t now appears from the experiments which I have described that the oxygen process might not only pass a water containing such an albuminoi'd as good but it might also pass a water containing pernicious products, since it is possible to obtain such 8r sdutiou which will exhibit a much smaller capacity for oxygen than the original fresh solution from which it is derived. So far as these experiments go they confirm the fact (which has been more than once disputed*) that putrefaction can begin and proceed in the absence of oxygen (that is as such) and in common with some researches of Nenckit they confirm the history of putrid fermentation as laid down by Pasteur.I n some of the experiments the putrescible solution showed in the next earlier stages a tendency to undergo slightly greater oxidation thau at the start ; it may be because up to this time the agencies at work consisted mainly of a hydrating character ; but as this proceeded and the quantity of available oxygen from without increased other agencies initiated amd carried on the oxidising influence constituting the second act of ordinary putrefaction. It would seem also that in soine of the experiments the agencies at work had the power of obtain-ing oxygen from within the mixtures for the quantity of oxygen available as air w m in certain instances no0 sufficient to account for the decrease in oxygon-absorbing capacity if we regard that decrease as due to interim oxidation.The presence of free oxygen doubtless assists the later changes. Finally it will be seen that in the history of putrefaction there comes a time when the activity of the agencieB at work greatly diminishes and finally almost ceases. No doubt this is due not merely to the using up of material ready to undergo putrefactive changes but also to the poisonous influence of the putrefactive pro-ducts when present in certain amount upon the agenta themselves. This has been well shown by Cmce-Calvert and Thornson Nencki, and others. Such a result is comparable with another observed in the process of alcoholic fermentation. So soon a3 the alcohol reaches a certain * For instance by Gtunniug in J. pr. Chem. [2] 19 266. t See paper by Nencki ibid. [19] 337-358; Abstracted in Chem. SOC. J., $ See a pamphlet by W. Thornson " On the Principal Agencies of Putrefaction Manchester (Palmer and Howe) 1875. November 1879 page 953. and Decomposition. 22 WRIGHT AND MENKE ON NAXGANESE DIOXIDE. amount fermenation ceases because the yeast cells are rendered inac-tive by the alcohol.* The ground-work however is not sufficient t o admit of much theorising and had it not been for the interest which the results origi-nated as to the oxygen process of water analysis I should not have submitted the experiments in their pbesent incomplete form