THE ANALYST. 187 THE ADMIXTURE OF OATXEAL WITH BARLEY MEAL. By E. L. CLEAVER, F.C.S. Read before the Society of Pu6lic Analysts, on the 18th Jammy, 1877. IN a case recently decided at Hammersmith Police Court, I stated that all samples of oats which I had up to that time examined contained barley in varying proportions, and that, consequently, I did not consider that oatmeal could be obtained free from admixture with barley meal.188 THE ANALYST.This statement has been much disputed by oatmeal manufacturers, and I have, therefore, gone very fully into the matter, and the object of this paper is to point out the real facts of the case as to the actual amount of admixture that may arise from unavoidable causes. The oats at, present in the market may be roughly classed into three divisions: English, Scotch, Foreign; and if these are closely examined, it will be seen that most of the foreign contain considerable quantities of barley, in some cases to the extent of 10 per cent.A few kinds of foreign, such as Russian, some kinds of Swedish, and Archangel oats, however, contain but very littie barley indeed, The English also contain barley, but nst, on the average, to the extent of more than two.or three per cent., whilst Scotch are practically quite free from barley, although a grain may occasionally be met with.The pract'ce of growing an oat crop after a barley crop, doubtless, accounts for some of the admixture, but not to the extent above mentioned; and it must be borne in mind that as barley is, weight for weight, cheaper than oats, there is some incentive to mix the one with the other, That this is sometimes done there is no reasonable doubt, and I believe that notices have lately been sent to foreign ports, warning shippers against so doing.The next question that arises is how much of the mixed grain is used in the manu- facture of meal ? The greater part of the oatmeal a t present consumed is, I believe, manufactured in Scotland, and by tacit agreement between miller and consumer is supposed to be made from Scotch oats; indeed, a glance at the different varieties of oats will at once show the superiority of the Scotch over other oats for the manufacture into meal, as it is very broad in proportion t o its length, and has a remarkably thin skin.Towards the middle of the year, however, supplies of Scotch oats begin to run short, consequently increasing the price, and some makers are obliged to purchase other sorts for conversion into meal.The varieties occasionally used for this purpose are the finer sorts of Swedish and Archangel oats: which always contain small quantities of barley, but the amount so introduced into meal cannot be great, never exceeding one or two per cent,, and often below that quantity .I have, therefore, come to the conclusion that oatmeal can be obtained practically pure, and that any admixture of barley above one, or at the most, two per cent., is deliberately made for the purpose of cheapness, or obtaining more profit on the sale of the meal. I now pass to the consideration of the means of detecting barley in oatmeal.A method was published in the Chemical News, some time since, by Nessrs. Pattinson & Stead, and I think the method to be for the most part very good, but I have found that it is not easy to obtain the meal so evenly distributed under the slide as I could wish, and I also think that the continual rubbing the cover on the slide is apt to cause the barley granules to be moved out from under the cover, and to aggregate just outside its edge, the reason, I suppose, being that they are so much larger than the oat granules.The method I hare adopted is as follows:-I take the barley and oats, mixed in the proper proportion, according t o the standard required, and pound them well in a mortar. I then separate the husks, and pass the powder through a wire sieve of about 40 meshes to the linear inch.I then dry the powder at a gentle heat over a water bath, and put itTHE ANALYST. 189 into a stoppered bottle. Five grains of thc powder are put into a small mortar, and rubbed with liquid (that used by myself being a mixture of equal parts of Gly- cerine and Alcohol), for a few minutes, until a smooth paste is obtained.I then add more liquid and wash out into a small measure, and make up t o the hulk of Q a fl. oz. After well stirring with a glass rod, a drop is taken out, placed on the slide, a small glass cover dropped upon i t and gently pressed down. The slide is then ready for observation of the number of granules of barley starch which appear in the €old. When testing a sample of oatmeal, the meal is treated exactly as stated above, and compared with the standard sample, whence the admixture of barley is easily calculated. The advantages I claim for the method are, that- First.-The meal and standard samples are, by drying, deprived of their water, consequently the same weight of substance is taken in comparing samples, which would not be so if not dried, as oats and oatmeal contain different proportions of water.Second.-The danger of rubbing out the granules from the field is entirely obviated: Third.-The quantity of material under the slide is always constant in different experiments. The precautions to be observed, are : firstly-to thoroughly pound the material, and take care it all passes through the sieve; secondly-to well stir the liquid before taking out the sample drop, as otherwise, owing to the greater weight of the particles of barley meal, they will subside t o the bottom, leaving the supernatant liquid comparatively free from barley.Also care must be taken not to confound the large compound bodies of the oat with particles of barley starch ; but if the rubbing with the liquid in the mortar has been properly done, these bodies will all be broken up.They are easily seen by taking an oat grain, cutting out a morsel, and putting it on the slide with a drop of liquid. I f a cover is then gently placed on the drop without much rubbing, these bodies will appear all over the field. They are more pear-shaped than barley starch granules, and by rubbing the cocer over the slide can easily be broken up, and the field then presents the usual appearance of oat starch.Dr. Muter said that he had read the evidence of Mr. Cleaver, as reported in the papers, with feelings of regret, as it was just the description of evidence which so greatly tended to bring analysts, as a body, into disrepute ; especially when men, without giving proper attention to their subject, too frequently are apt to be pitted against those who have thoroughly studied and practised the matter that may, for the moment, be under discussion.Many of those present, no doubt, had already felt the absurdity of this so- called defence-evidence. Oatmeal was a subject upon which he could speak with some amount of authority, being a Scotchman who was brought up upon that most excellent diet, and having from the first moment of his possessing a microscope made it one of his amusements, even as a boy, to test the quality of the meal he consumed.The published statements of Hr. 'Cleaver having apparently made a sensation in the meal trade, he had been called upon to examine lately a larger number of samples than usual, and he could state positively that no sample of genuine ficotch oatmeal ever contained, unless by design, any distinct quantity of either barley or wheat.Of course190 THE ANALYST. oatmeal was a commercial article, and now and then a few granules of foreign starches would appear under the microscope ; but they were so few that no analyst would take any notice of them as deliberate impurities. B e presumed Nr.Clearer had led himself into error by examining samples of Russian oats, which are well-known in the trade to be imported for cattle-feeding purposes, and are not suitable for making oatmeal. Most samples of these oats certainly do contain corns not only of barley but of several other cereals, together with seeds of tares, &c., but even in the most unclean samples these few corns would never produce any distinct per centage, such as 15 or 20, in the manu- factured meal.It was necessary to be careful in examining any sample of oatmeal to see that one was not deceived by the round masses found in genuine oats, and exactly simulating barley, especially when using lamp light. On the other hand, if an adulter- ation of barley were really present it is necessary to be very careful, and calls for the employment of great experience.This is owing to the large number of small granules found in barley starch, measuring 000073, and which have, in many cases, a decided tendency towards a certain angularity that renders them very liable to be confused with the larger oat granules. He would not have much confidence in the ability of many analysts t o distinguish barley from wheat in the presence of oats.If, however, by the judicious use of the light and micrometer, the presence of barley be really established, the best criterion to go on for the estimation of the percentage, is the number of granules measuring $00292 which are found in barley to bear a very constant relation to the *00073 granules already referred to.I n conclusion he believed that his colleagues now present would bear him out in the fact that, given an admixture of say 5 per cent, they would consider it a most decidedly adulterated sample. Mr. Allen expressed his opinion that Mr. Cleaver had not sufficient evidence to justify him in going into Court to oppose the analysis in question, and Dr. Hill spoke to the same effect.Nr. Hastie, having thanked the president for being allowed the privilege as a visitor of speaking, remarked that he was much interested in the question, being a manufacturer in Scotland of oatmeal, and a wholesale dealer in London, and he could, with confidence, Bay that all the oatmeal which he manufactured and sent out was made from the finest Scotch oats that could be obtained. With regard to some remarks which had been made about oats and barley being grown together in some districts in England, such a practice is unknown in Scotland, and the only way in which a few grains of barley or wheat could get into a parcel of oats is from the thrashing machine, which may have been thrashing barley or wheat before the oats, and consequently a few g r h s of either may have been left in, but the proportion is so small as to be scarcely perceptible. He had had three samples drawn from the bins of oats in his mills in Scotland, two of which he found absolutely pure oats, but the third contained 2 grains of barley in 1,250 grains of oats, and he considered this as pure as they could be produced.To talk of 5 , 10, or 15 per cent.as not being adulteration was simply absurd ; there was no doubt whatever that a deal of the oatmeal sold in London was adulterated, but the present enquiry would, probably, have the effect of putting a stop to a practice that has been carried on for years. Mr. Dyer remarked that he had found considerable proportions of barley-meal in oztmeal sold for cattle-feeding purposes.He thought it possible that in some rare instances this admixture might be attribuhble to the custom which was Laid toTHE ANALYST. 191 prevail to a certain extent among farmers in some parts of England, of growing oats and barley as a “mixed crop,” the meal from the mixed grain finding its way into the market as (‘ oatmeal.” Mr. A. H. Church had analpsed both barley meal and oatmeal, and had examined many samples of the grain of these two meals.The casual weed seeds and barley grains which he had detected in such samples of oats as were used in the manufacture of oatmeal, if not originally below 1 per cent., would be reduced, and are reduced below that figure in the opcrations subsequent to kiln drying, to which the oats are submitted. He had found Scotch oats to be of remarkably good quality, while the oatmeal made from them, often contained 10 per cent.of fat, and less than 5 per cent. of moisture, when fresh. The speaker had, however, found that the barley-meal used for pig feeding was liable to a serious adulteration with a preparation, known in the trade as ‘‘ mixing stuff.’’ This substancc consisted of ground gypsum, to which from 10 t o 25 per cent.of coarse barley-dust or similar products from the cleaning of rice, or oats has lieen added. Nr. Thomas said he was connected with agriculture, and thrashing oats by portable steam machines led to a slight admixture mith other corn lodged in the machine from tt previous thrashing. It should not amount t o one part in 10,000, and more than one per cent.ought to be regarded as adulteration. Mr. Wigner pointed out that it was clear that Mr. Cleaver must have gone into Court mith the evident intention of upsetting Dr. Duprd’s analysis, if possible, and that such a course was not only unprofessional, but the evidence, as reported, and the paper read this evening showed that the gentleman in question had not made himself fully acquainted with the subject.He, the speaker, had himself examined the samples of oatmeal in question, and was convinced that Dr. nupr6 was within the bounds of truth, when he stated the adulteration at 35 per cent. He thought it was extremely to be regretted that a public analyst, whose duty it was t o protect the public from adulterations of every kind, should sacrifice his reputation by going into Court for the defence, when no legitimate case for defence existed, and suggested that Mr.Cleaver should write a letter to ( ( The Analyst,” stating that having considerably extended his knowledge of oatmeal since the hearing of the case, he is now of opinion that oat,meal can be obtained practically free from barley meal. Mr. Vogan said he thought it useless t o go into ingenious theories as to the way in which barley and wheat got mixed mith oats before grinding, because all who understood the manufacture of oatmeal were perfectly aware that there is in fact no such mixture t o any discernible extent in such oats as are used by honest manufacturers.He would be sorry to say anything unkind of Mr. Cleaver, but he thought that gentleman would have acted more wisely if he had made himself acquainted with the facts before he reported upon the meal.Mr. Cleaver came to Mark Lane, and was shewn round the market by the gentleman who was implicated, and saw many samples of oats, and he stated that lie found a large percentage of barley in all of them ; this was no doubt true, but unfortunately, the oats he saw were not such as are used for the pnrpose of making oatmeal.He (the speaker), was an old Mark Lane a a n , and although neither a chemist nor an analyst, he had heen familiar with the use of the miscroscope for many years, and his friend Mr. Hastie asked his opinion upon this subject, and introduced him to Mr. Cleaver when he came to Nark Lane, biinging with him a sample of oatmeal which he pronounced to be adulterated. Ur.Clearer showed us certain discs, which ‘( he would192 THE ANALYST. stake his life were barley granules.” He, (the speaker) took a portion of the impugned sample home, and ‘having made himself carefully acquainted with the appearance of barley starch by polarised, direct, transmitted, and diagonal, light he found the discs referred to, but was convinced that they were not barley at all, but the agglomerated granules always found in oats, Mr.Cleaver had evidently made an error, and he should take some steps to clear himself from the unpleasant position in which he had placed himself. Dr. Duprk after expressing the pleasure felt by the Society in seeing several members of the corn trade amongst them this evening, remarked that a speaker had alluded to the declaration of the magistrate, which had appeared in some of the papers, that an admixture of 15 per cent., or less of barley meal in the sample in question would be allowed to pass, but that a fine would be inflicted, if more than 15 per cent, were found.Knowing that the sample contained more than 15 per cent., he did not think it worth while to raise any discussion on this point. At the adjourned hearing, the magistrate however stated that this limit of I 5 per cent.was not t o be taken, as forming in any way a precedent for future cases, for he knew that Scotch oatmeal could be obtained with a much leas proportion of barley meal; unfortunately this statement did not appear in the papers. The Society is, however, indebted to Nr.Cleaver for bringing the subject forward this evening, since it has shown that, in the opinion of every one here present, practical men, as well as analysts, anything more than 1 per cent., or at most 2 per cent. must be looked upon as adulteration. He hoped that this unanimously expressed opinion mould once for all settle the question, and render a dispute between analysts on this point impossible for the future.I n conclusion, he expressed a hope that Mr. Cleaver would follow Mr. Wigner’s advice, and write a letter to “ The Analyst,’’ stating, that having considerably extended his knowledge of oatmeal since the hearing of the case, he is now of opinion that oatmeal can be obtained practically free from barley meal; l l r . Cleaver owed them he thought some amends, and he could not offer them in a better way than by writing the letter suggested.Mr. Cleaver, in reply, said that the published reports of the case were so erroneous that he was not surprised at the severe criticisms that had fallen from the several speakers, he would however, give them the true facts of the matter. A corn dealer was summonsed by the Westminster authorities for selling oatmeal adulterated with 35 per cent. of barley meal, and he came to him to analyse a similar sample.This he did, and found that it did contain about 20 per cent. of barley. The dealer then said that it was impossible to obtain pure meal, and in support of this statement accompanied Mr, Cleaver to Mark Lane, where they examined a large number of simples of oats, as imported, all of which contained barley, in one case to the extent of 15 per cent. Whether these oats were used in the manufacture of Meal was not asked by him (Mr. Cleaver), and he regretted not having done so, as it would have saved him great annoyance, still his evidence was correct, as far as it went; but he must acknowledge that the deduction drawn, that oatmeal cannot be obtained pure, is incorrect. With regard t o what Mr. Vogan had said, he thought there was some misunderstanding on that gentleman’s part, as he (Mr. Cleaver) merely told him that there were a few barley granules t o be seen, but not t o a great extent, and he had since told Mr. Hastie that i t Was under 1 per cent. He did not think that there was any chance of his having made a mistake, especially as regards confounding the compound bodies in the oat with barley starch, as he had particularly mentioned those bodies in hie paper.