58 HARTLEY SPECTROSCOPIC NOTES OX THE VII.-8pectroscopic Notes on the Carbohydrates cnzd Albuminaids from Grain. By IV. N. HARTLEY F.R.S. Professor of Chemistry Royal College of Science Dublin. ACCORDING to C. v. Nageli (“ Theorie du GGhrung”) fermentation is a pyocess which may be described as the transference to fermentable matter of the molecular or rather intramolecular vibrations of the differant constituent substances entering into the composition of living protoplasm (which remains itself unchanged in composition) and herice the equilibrium of the molecules of the fermentable matt’er becomes so disturbed as to cause their resolution into simpler mole-cules. In this case the intramolecular vibrations of the substances are transferred through the cell-wall of the saccharomyces to the molecules of sugar outside.It appears by no means improbable that the diastatic ferments may have some such action; therefore any facts bearing on this matter are of interest. The vibrations of the active substances must be either of greater amplitude than those of the carbohydrates or else of much greater frequency ; for if of the same frequency but of lesser amplitude they could not cause any such effect as that described. Now it seemed to me to be possible to learn something of the mode and rate of vibration both of the molecules of the carbohydrates and of the diastatic ferments. Accordingly I have photographed the absorption spectra transmitted by solutions of saccharose glucose and starch as also those of several albumino’id compounds and egg-albumin.For specimens of diastase from malt and invertase from yeast I am indebted to Mr. Cornelius O’Sullivan who kindly placed specimens at my disposal some two years and a half since with the offer of a further supply if necessary. While the work was in progresB M. I;. Soret published his fift CARBOHYDRATES AND ALBUMINOIDS FROM GRAIN. 59 memoir on the absorption of ultra-violet rays by different substances, which included an examination of the various forms of albumin (Archives des Sciences Physiques e t NaturelEes 10 139 ; Cornpt. rend,, 97 642) the carbohydrates glucose saccharose and gelatin. My results proved to be in strict agreement with his as regards these snbstances ; it is proposed therefore to give them in abstract only. Considerable difficulty was encountered in photographing some of the liquids on account of their opalescence which prevented more than thin layers of liquid from being examined.In one or two cases as with gelatin and with starch the liquid was allowed to dry on plates of quartz and the rays were passed through the dried films. This proved decidedly advantageous but on the whole the turbidity of the solutions has been a source of much trouble. GeZatin.-(1.) A yellow specimen sold for photographic purposes, said to be of Nelson’s preparation b u t without any distinchive label. A solution containing 5 per cent. of the solid and 1 mm. in thickness was allowed to dry on a plate of qnartz. It transmitted a continuous spectrum to wave-length 2265 but beyond 2313 the rays were weak.(2.) A very fine colourless sample made in sheets which in the original form transmitted all rays to 2265. A solution containing 5 per cent. and 1 mm. in thickness dried on a plate of quartz transmitted all rays to wave-length 2265 in full intensity. Maize Xiarch.-Brown and Polson’s corn flour. A solution of 1 part to 12 of water and 1 mm. thick dried on a plate of quartz trans-mitted a spectrum of normal strength as far as wave-length 2145. Cane-sugar.-A solution Containing 10 per cent. transmits all rays through as much as 25 mm. as far as wave-length 2145. Very highly diactinic. A solution containing 10 per cent. transmitts all rays through a thickness of 10 nim. as far as 2145. According to &I. Soret’s measurements, the following wave-lengths have been reckoned :-2 mm.diluted with water twice from about Glucose.-A very pure specimen. Albunzin.-White of egg. Absorption-band. 2880 to 2650 34 3 , five times from I ¶ I , 4 9 3 , nine times , 9 9 9 The same absorption-band occurs when albumin is acidified. Pure Albumin.-When a solution of pure a1 bumin containing 37 grams per litre is examined 2 mm. of the liquid exhibit an absorption-band from about 2948 to 2572 wave-lengths. Cmezn.-A solution containing 6.5 grams per litre. 8 mm. and 9 rnm. 8erin.-Solution containing 10.5 grams per litre. 4 mm. t o 5 mni. A similar band. Absorption-band from about 2948 to 2572 60 HARTLEY SPECTROSCOPIC NOTES. Solutioiis of invertase and diastase were prepared from Mr. O’Sullivan’s specimens.Invertase was also prepared from compressed porter yeast by simple treatment with water and filtration the yeast being from the brewery of Messrs. A. Guinness and Sons. The solu-tions were difficult to examine especially the diastase; the con-siderable quantity of matter dissolved rendered filtration difficult, and they showed a certain degree of turbidity not easily removable. The possibility of manipulating the liquids so as to clarify them was interfered with by reason of the facility with which they putrefy and the necessity of avoiding the addition of any preservative to them. The following is a description of the spectra :-Invertase.-A solution containing about 1 per cent. or 0.1 grani dissolved in as little water as possible between 8 C.C. and 10 c.c. and filtered.Wave- Oscillation lengths. frequencies. 20 mm. continuous spectrum to 2418 4136 15 ?7 7 7 7 2313 4326 10 9 9 9 2263 4420 5 4 and 3 mm. continuous spectram to 2193 4555 2 and 1 mm. continuous spectrum to. 2148 4658 Yeast Water.-The same result was obtained as with invertase. Diastase.-A solution containing about 1 per cent. or 0.1 gram in 10 C.C. of water. The turbidity of this solution weakened the spectrum throughout when a thickness of 10 Em. was examined. Wave- Oscillation lengths. frequencies. 10 mm. 9 mm. and 8 mm. con-tinuous to 2988 3359 A strong line faintly visible at 2568 3890 7 mm. and 6 mm. continuous to 2568 3890 The albuminoYds invertase and diastase are eridently of very dif-ferent constitution from albumin casein and serin all of which as Soret has shown have something in common which is disclosed by the absorption-band common t o their spectra.Gelatin tliff ers from these forms of albumin. While albumin casein and serin exhibit absorption-bands in dilute solutions and in small thicknesses of such solutions gelatin invertase diastase starch glucose and smccharose, under like circumstances are seen to be highly diactinic and show no absorption-bands. It does not therefore appear likely that a sub-stance of the character of albumin could affect the carbohydrates, while on the other hand it is possible that the intramolecular vibra DTSON THE ACTION O F SALICYLIC ALDEHYDE. 61 tions of invert'ase and diastase might be communicated to sacchaross and starch. Froin this of course it folIows that there may be in yeast-water or within the yeast-cell some similarly constituted albu-mino'id capable of acting on glucose in a manner similar to the action of invertase on saccharose but yielding different products.Setting aside theoretical considera,tions touching fermentation it is of great interest to find that substances of such complex coinposition as the sugars so extraordinarily diactinic for this is quite in character with what we know of their constitution. It is no less interesting to learn that the albumino'id compounds associated with the carbo-hydrates are evidently different in constitution from those forms of albumin found in the animal organism. The probability presents itself of these albuminoi'ds being derived from the carbohydrates.The examination of specimens of gelatin shows that the difficulty in obtaining photographic plates sensitive to the most refrangible rays, lies entirely with the character of the gelatin. Ordinarily the spectrum extends Do wave-length about 2146 Cd. Some plates prepared many years ago by Wratten and Wainwright called ordinary dry plates, were used for photographing a series of metallic spectra which extend to wave-length 2024 Zn and there is little doubt that they were capable of receiving impressions of lines still more refrangible. Since then plates of every kind by every maker have been tried but most of these transmit nothing beyond 2146 Cd. A sample from Mawson and Swan was recently found to photograph as far as 2024 but half a dozen other batches from the same makers were deficient in this respect notwithstanding that they were supposed to be of exactly the same character. As the plates were prepared in precirely the same way there can be no doubt that the difference was in the gelatin which must have contained some very slight trace of impurity which could not otherwise be detected