content and a lower refractive index, but on the other hand, the fat content is increased.

2. Thus this milk would be passed as excellent in quality, unless the data obtained by its examination were compared with those referring to the product of healthy cows.

3. It appears, from the data obtained, that a change in the methods hitherto adopted for milk control is not necessary if all the characters of milk are considered together.

61 A Quick Method of detecting Water in Buttermilk.

HÖYBERG, H. M. Ein schnelles Verfahren zur Bestimmung des Zusatzes von Wasser in Buttermilch. Zeitschrift für Fleisch- und Milch-hygiene, Year XXIII, Part 5, pp. 104-107. Berlin, December, 1912.

Hitherto, it has not been very easy to determine whether water has been added to buttermilk or not, especially when it was impossible to prove the presence of nitrate, the latter substance being absent from some waters; further, it may be introduced by the water used for washing.

Therefore in legal proceedings the only method at present employed for judging the purity of the buttermilk is the determination of the solidsnot-fat content, for the fat content is too variable to be used for this purpose. The writer proves by his experiments that the solids-not-fat content of buttermilk often sinks below the usually accepted minimum amount without any addition of water, while it often remains higher even when water is added. Also, from the solids-not-fat content it is impossible to determine the quantity of water present.

Another more accurate method of determination must therefore be adopted. Such, for instance, as estimating the specific weight of the butter milk and whey.

As the thick consistency of the former prevents its specific weight being determined in the usual manner by an areometer, the writer obtained it from the whey contained in the buttermilk.

He heated 1⁄2 litre of buttermilk to 50° C., pressed the buttermilk through a piece of thick linen, and cooled it to 15° C. He then determined the specific weight in 112 experiments by means of an areometer and obtained the following data.

The whey of unadulterated buttermilk has a specific gravity of from 1.0250 to 1.0275.

If the specific gravity of the whey is below 1.0250, the buttermilk may be regarded as adulterated with water.

Further, the ratio between the specific gravity and the amount of water added remains constant, i. e. the specific gravity falls on an average 0.0010 with every 5 per cent, addition of water; thus this method affords a means of determining with some accuracy the amount of water which has been introduced. In this way, adulteration in buttermilk samples can be quickly, easily, and sufficiently accurately detected.

In conclusion, the writer remarks that it is necessary to distinguish between direct and indirect watering of the buttermilk; the latter occurs from steam being passed through, or if ice is added to the cream in order to cool it.

Further, water may be introduced if the milk utensils, e. ing apparatus, are not water-tight.

g. the cool

CLARK, WILLIAM MANSFIELD: U. S. Department of Agriculture, Bureau of Animal Industry. Bulletin 151. September 7, 1912.

The writer aims at ascertaining by means of exhaustive experiment the nature of the gases present in the so called “ eyes" in Emmental cheese, and of those which cause the formation of these cavities. He succeeded, by means of apparatus devised by himself, not only in collecting the gases in the eyes, but also those in the "pinholes". These he subjected to qualitative and quantitative analysis.

In normal eyes, the gases consisted of carbon dioxide and nitrogen with traces of oxygen and hydrogen. Spectroscopical investigation also showed that hydrogen can play no part in the eye formation, as no significant amount of hydrogen was found, and it was proved that this gas had not escaped detection from its rapid diffusion out of the body of the cheese. The production of hydrogen was however very active while the cheese was in press, and small percentages of this gas generally accompanied abnormal eyes. This is probably due to a slight initial gaseous fermentation of the sugar. It has, however, been shown, that all traces of sugar have disappeared by the time of the formation of normal eyes, and further, that sugar fermentation and the formation of hydrogen have nothing to do with the production of these cavities. In the ripening process of the cheese, therefore, two types of gas formation. are to be distinguished. The one is highly detrimental and is accompanied by hydrogen, while the other is demanded in a good Emmental cheese. One is dependent upon the presence of sugar, the other occurs in the absence of sugar.

With regard to the oxygen, the writer found that a large amount of this gas was absorbed by the cheese, but only small traces of it were found in the cavities. Oxygen is also absorbed from the air which penetrates the cheese, but the nitrogen remains in the eyes.

Emmental cheese has a low permeability for air and for gases in general, especially when it is dry. Only a small amount of air can penetrate into the cheese, and since the oxygen contained in this small quantity of air is absorbed, it follows that the conditions in the interior of the cheese are eminently favourable to the development of anaerobic bacteria.

The nitrogen which is found in the mixture of gases in the eyes is also partly derived from the air which penetrated the cheese, but mostly, as was proved by experiment, from that contained by the

WOOL INDUSTRY

curd. It can, however, be considered certain that no free nitrogen arises in the formation of the eyes.

Only carbon dioxide plays an important part in the formation of these cavities and forms the greatest part of the mixture of gases contained in the latter. Von Freudenreich and Jensen considered that the formation of carbon-dioxide in the eyes was due to the activity of propionic bacteria, but the writer proved mathematically and practically that the action of these micro-organisms is not sufficient to account for the large amount of carbon dioxide which is formed during the ripening of the cheeses, for the whole amount of the gases formed not only occurs in the cavities but also saturates the body of the cheese. Further, a large increase in the formation of carbon dioxide takes place if the cheese is manipulated with sterilized instruments.

If the bacteria are indeed concerned in the production of carbon dioxide, the question still remains whether they are sufficiently localised to cause the eyes. The writer suggests that there are two phases in the formation of normal eyes, a saturation of the body with carbon dioxide, and an inflation of the eyes. He allows that the part played by anaerobic bacteria in gas production is an important one, but leaves it an open question whether their action in the formation of eyes is primary or secondary. The writer notes in this connection that a number of cheeses made with artificial rennet, which did not contain propionic acid bacteria, began a normal eye formation, but as this begin ning seldon developed into normal holing, he asks if it is not possible that the reaction which started the eye formation was rendered inadequate because the gas-producing propionic bacteria, which might have saturated the cheese with carbon dioxide, were absent. He is, however, of opinion that exhaustive research and the qualitative and quantitative investigation of the gases at every phase of cheese-ripening can alone solve the question.

63

Insects Infesting Woollen Tops. FROGGATT, WALTER W. The Agricultural Gazette of New South Wales, Vol. XXIII, Parts 6 and 10, pp. 491-492 and 900 + 1 plate. Sydney, June and October, 1912. In the first of these articles the writer ascribes the injury done to a package of woollen tops, which had been shipped from New South Wales to Japan, to a cosmopolitan carnivorous species of the Cleridae, Necrobia rufipes, called the "Red-legged Ham Beetle" in England, because it feeds upon ham, etc.; in the Islands it is known as the "Copra Bug", as it devours dry coconut kernels. This insect was determined by the writer from specimens of infested tops sent to him from Japan.

After the publication of his account, several authorities among the shipping people observed that the woollen tops were destroyed, not by the "Copra Bug," but by a weevil. In a second lot of samples of tops sent from Japan, the writer discovered other larvae different from those which had been present in the first consignment; these proved to be the larvæ of Dermestes cadaverinus (" Cosmopolitan Skin Weevil "). This destructive

insect is plentiful in sheep-breeding centres and in hide and skin stores. Dermestes cadaverinus occurs most commonly in ships which trade between Australia and the Far East. It is not only necessary to fumigate the holds of such vessels as carry hides, skins and bones, but further, all the loose fittings should be examined and removed if infested with these insects.

64

de Màrc ".

-

Annales des Falsifications, 5th Year, No. 49,

- "Vin de Goutte" and " Vin Roos, L. Vin de Goutte et Vin de Marc. pp. 509-517. Paris, November 1912. The writer gives the name of "vin de goutte to the wine which flows by itself from the grapes, whether the latter are crushed or not, while “vin de marc" is that which remains in the solid particles of the fruit after draining and which is extracted, either by pressure before or after fermentation, or by diffusion after fermentation alone.

There is a great difference in composition between these two kinds of wine made from the same vintage, and notably in the alcohol content, which might lead to the suspicion of adulteration. The method of winemaking used, the system, or the completeness of the crushing, the development of the mechanical apparatus attached to the crusher for separating the juice or removing the stalks, the submerged or the floating pomace systems of fermentation, and the degree of the ripeness of the grapes, are all factors in determining the differences, which are often great, between the "vins de goutte" and "vins de marc" from the same vintage, i. e. between the "vins de goutte" and those which are, later on, pressure wines or diffusion wines according to the process employed for exhausting the pomace.

M. Bouffard has already obtained, by means of laboratory experiments, a difference of 0.6 between the average degrees of two pressure wines from the same vintage, of which part was thoroughly, and the other only half crushed.

The writer has observed numerous cases where "vins de marc" resulting from the method of mixed wine-making, by which it is proposed to make from the same vintage and at the same time, white or rose-coloured and red wine, have an alcohol content 2 or 3 per cent lower than that of the "vins de goutte". If the different parts of the grape are examined, it will be seen that the decrease in alcohol is due to the vegetation water of the fruit occurring in part of the grape only. According to M. Girard and Lindet 1000 kg. of Aramon grapes furnish :

WINE-MAKING

These figures, if applied to 959.3 kg. of grapes, give for 1000 kg. of a complete vintage:

The 851.95 kg. (1874.29 lbs) of pulp, of a density above unity, correspond to 800 litres (176 gallons) of juice. Thus, if from such a vintage when crushed, on the first operation 500 litres (110 gals.) of juice are obtained, there still remain 300 (66 gals.) in contact with the solid parts of the fruit forming the pomace of this first pressing. The composition of these portions is as follows, according to the same analysis of M. Girard and Lindet.

The percentage composition of the Aramon skins is considered to be:

It should be noticed that the other substances, summarized at 23.20, do not include sugar. The percentage composition of the pips, which do not contain sugar, is :

After complete fermentation, lasting long enough to allow of cellular interchanges, and finally of the pomace becoming impregnated with a homogeneous liquid, all the vegetation water of the skins, pips, and stalks unites with the remaining 300 litres (66 gals) of juice.

Thus the amount of water would be for the 1000 kg of the grapes under consideration:

The 300 litres of fermenting juice are thus united, by means of intercellular exchanges, to the 107.300 litres of water to form a homogeneous whole. If also the amount of sugar present is as allowed for by MM. Girard and Lindet 14.09 per cent. of the pulp weight the juice in question would contain 150 gr. per litre, capable of giving a vin

150

of =

8.57 per cent.