| Show adulterations ADULTE RATIONS OF MILK 7 an editorial under the th e heading testing adulterated Adulte raed milk in the EVENING NEWS of saturday the irth is ib the immediate cause of this article I 1 thought that perhaps a few notes on the best methods of detecting milk adulteration might be of interest and perhaps of practical value to some of your readers human nature seems to be the same the world over the greed for gain the haste to become rich the ambition to get the largest possible return for the least possible outlay seems to be everywhere present the adulteration of many kinds of manufactured products is all too common but it is the adulteration of our food products that is of most I 1 importance to us as it not only affects the pocket but may also assail the health these matters should be sub ejects tor for legislative action not only in in the different states but by the national government the petty thief who robs the consumer of his goods by selling him an adu aerated article for the genuine should be treated the same as apy any other thief so that society may be protected from his depredations the adulteration of milk is unfortunately too common not only in our cities but also in those districts where milk is sold to butter and cheese factories the practice of adulteration is by no means of recent origin though the means of detecting it is the most common methods of milk milic adulteration is either skimming removing some of the cream or watering other forms except perhaps the use of preservatives are so rare that but little notice need be taken ot of them the detection of these adulterations adulte rations belongs largely to the field of the chem 1 though it does not require much chemical knowledge to test milk in case there is is suspicion of disease germs being in the milk a biological examination may be necessary but as the infection generally arises from the milk i being delivered from a home where the disease is is pre present seni or particularly in the case at typhoid fever in the use of impure water to wash or rense the milk vessels or perchance to adulterate the milk a thorough inspection will generally check those evils and render a biological examination unnecessary except in rare cases those who would like to be thoroughly sure on these points have the remedy in their own hands if they will take lake the trouble to pasteurize their milk any home possesses the necessary apparatus for the work take an ordinary mason jar or a milk bottle size will derendon de depend pendon on the amount ot of milk to be traded wash thoroughly scald fill with milk and put on the cover take a tin pail 8 or io 10 quart size perforate the bottom of a tin nn plate and place it bottom up in the pail and stand the bottle of milk on this fill the pail with warm water up to the level of the neck of the jar or bottle put the whole on the stove and heat the water to degrees F hold at ai this temperature lor for halt an hour when the jar ot of milk should be removed and cooled quickly those who haye have no thermometer ther may bring the water just to a boil then remove from the stove immediately delay will give 3 cooked taste and keep the milk in the water for half an hour then cool and keep cool this treatment will kill or so awaken all disease germs as to render them harmless particularly if the milk is afterward kept on ice this treatment also increases the keeping qualities of the milk by twenty lour four to forty eight hours and makes it a much safer food for infants at all seasons of the year the year book of the department of agriculture at washington D C describes this matter thoroughly and probably may be had on application the detection of adulteration as at present practiced edis is like many other things the result ot of a process of evolution three or four instruments were formerly used the lactometer gave the relative weight of the milk milk is heavier than water and so the addition of water made the milk relatively lighter but cream had the same effect and skimmed milk is heavier than whole r wilk milk thus the lactometer alone would not do and other tests were used as checks the a german in ven dention venti tion oo is a glass tube and aims to give r the approximate per cent of fat in the milk A definite quantity of milk is diluted with water in the tube till the black marks on a white column in the 74 centre of the tube are distinctly visible t the more water it is necessary to add 1 the richer the milk is in fat the pia scope is a black dish with a glass cover the latter is transparent in the centre but the outside is divided into five or six parts by different colors radiating from the centre raging from a creamy white to a light blue A drop of milk is placed in the centre of the black dish and the blass cover put on the milk can then be compared to the color which best describes it from cream to poor skim milk the cream guage is is simply a glass cylinder which is filled with milk and allowe I 1 to stand twelve to twenty four hours and the amount of cream which raises is is supposed to tell the rich ness of the milk these tests it can be seen acted as checks one on the other and were a great help towards an approximately correct guess as to the quality ot of the milk other tests have j f been introduced but have not been used to the extent of those described at the present time all of these tests are practice tica ly superseded though we keep them as relics of what till five years ago were the only cheap and simple method of testing milk ar ff the principles upon which the present methods for the detect detection ibn of adultery J eions is is based are the same as formerly but the means ot of obtaining our data and the method of using the same are much more accurate skimming milk reduce the fat and increases slightly the percentage ot of other solids ot of the milk watering milk decreases the percentage of tat fat and ot of other solids in direct proportion artion to the amount of water added the apparatus used is the babcock milk test the Que venne lactometer and a thermo with the babcock teta te ta description of which space forbids we determine accurately the percentage of fat in the milk the Que venne lactometer with the milk at sixty degrees F when immersed in the milk sinks until the amount of milk displaced equals its own weight the reading on the nick gives fives the excess of weight of the milk over the same volume of water with these facts at hand we apply the following formula L 47 70 F solids not fat in the 38 milk sac Que venne lactometer reading at IL L aop 60 F F the per cent of fat in the milk to illustrate the lactometer reading is 33 and the per cant of fat is 35 then 33 7 10 of 35 38 3 38 8 aj 93 per cent solids not fat fac in sample in n testing lot lor adulterated milk i it t is best beat for the inspector to get a sample direct from the farm where the milk is produced As the total solids in a sample of milk from a herd will rarely vary more than three tenths of one per cent from day to day a sample from the home bome r the dairy and the sample from the delivery can should practically agree if such a sample cannot be procured nine nine per cent solids not fat is taken as a basis of calculations as milk from a herd very seldom goes below 84 per cent solids not fat or above io 10 per cent the average being very dose close to nine then if we had a sample of milk which from our test and calculations gave us only per cent solids not fat and 2 per cent fat it is evidently a sample of watered milk not skimmed milk as a sample of this description was recently named in one ot of the salt lake papers except perhaps in a slight degree to find the amount of adulteration the question is if 9 per cent is the amount of solids not fat in pure milk how much pure milk is there in a sample containing 58 per cent solids not fat a question in proportion 9 50 50 per cent of pure milk which subtracted from aioo gives per cent the amount of water added if however we had a sample testing 2 per cent fat and 95 per cent solids not tat fat we know that such a relation never exists in pure milk and that it is partly skimmed milk by this method the students in our dairy laboratory can tell to within 2 per cent they often go closer of the amount of water with which I 1 dilute a sample if they have the original ginal to compare it wih whether th that at original be a sample ot or whole milk partly brimmed skimmed or skimmed milk ifan if an original sample cannot be obtained it can be seen that rich milk may be diluted to a slight extent without it being detected but human nature is such that sooner or later those men who practise it get too bold and add an extra quantity and w when hen a vigilant inspection is kept up such parties seldom escape with regard to other adulterations adulte rations other fats or oils a are ire never added addea to milk as it is impossible to emulsify them with the milk preservatives are not used and salicylic acid or a mixture of these are the most common their action is anti celtic delaying the action ot of organisms in small quantities they may be harmless but as they seem to accumulate in the system and finally work harm par ticul arly to children they should not be used several states and some of the european countries have laws against the use in any dairy products I 1 think these preservatives are seldom used as an excuse lor for adding water or to cover up such dilution any ordinary sample of of milk which does not thicken in twenty four hours in the summer time dine if kept at the temperature of the living room I 1 would suspect of being a preserved sample and it should be sent to a chemist for analysis even the adding of burnt sugar or even coloring of which are practiced to improve the appearance pe arance of the milk would not escape the detection of an expert more particularly ticul arly as only poor milk needs such treatment good milk requires no such propping up i to those who would like to study this subject I 1 would refer them to the eighth annual annual report of the wisconsin experiment peri ment station page also the ath and loth reports and bulletin no 36 some of them perhaps all may be oo 00 bained for the asking the dairy messenger no 2 contains a very full description of milk testing volumes no one to ten may be obtained from hoards D dairymen airy men for to those who would like to inquire further I 1 would advise them to take the course in agriculture at the utah agricultural college if they cannot take the four year course then take the two year or it not that then the special winter course the subject is thoroughly covered we have all the references given and many more to which the students have access yours respectfully L B LINFIELD utah exp eap station logan |
