October ii, 191 7] 



NATURE 



117 



scale of prices fixed for milk and the efforts being 

 made to secure reduced prices for feeding-stuffs and 

 a preferential call upon supplies, the dairy farmer was 

 being fairly treated, and should endeavour to sur- 

 mount his difficulties by securing greater economy in 

 the use of food and an increased average milk output 

 per cow. 



On the subjejct of beef production Mr. Prothero did 

 not conceal his apprehension that the scale of prices 

 fixed by the Food Controller for the winter would not 

 only gravely imperil our meat supplies, but would 

 even operate adversely against corn production. From 

 his practical experience he was convinced that current 

 prices left little margin of profit, if any," for the arable 

 farmer, who feeds and fattens cattle for the winter 

 market. A price of dos. per cwt. live weight for stall- 

 fed cattle puts a premium on grass as the cheapest 

 form of cattle-feeding, and thus renders the farmer more 

 reluctant than ever to plough up grass ; it penalises 

 stall-feeding on arable farms, and so tends to diminish 

 the supply of manure for the needed corn crops. We 

 are glad to see, therefore, the announcement in Wed- 

 nesday's Times that the War Cabinet has conceded the 

 appeal of the farmers for a revision of the scale of 

 maximum prices fixed some months ago for home- 

 killed beef for the Army. Under the sliding-scale of 

 prices for live cattle, as originally announced, the price 

 for home-killed beef fell from 745. per live cwt. in 

 September to 725. in October, 67s. in November and 

 December, and 605. from January i, 1918. It has 

 now been decided that the November and December 

 price of 67s. shall continue until July i, 19 18, and that 

 the 60s. maximum shall then come into force for the 

 rest of the year. 



At the best, with the reduced supplies of feeding-stuffs, 

 it will be difficult to avoid a serious shortage of meat in 

 May and June next year. We must not be driven to 

 slaughter more cows or veal calves ; we cannot depend 

 upon an increased import of meat ; the only safeguard 

 within our control is a reduction in our consumption 

 of meat, and this must be pressed for more and more 

 insistently. The eloquent appeal to farmers in the 

 closing part of Mr. Prothero 's speech will assuredly 

 not fall on deaf ears,- but it is equally necessary that 

 the public shall realise their difficulties and extend to 

 them the sympathy which no section of the community 

 more rightly deserves. 



T' 



CHEMICAL LABORATORY PORCELAIN.^ 



'HE first attempts to make porcelain in Europe 

 were undoubtedly in imitation of the Chinese 

 porcelain imported into Europe by the Dutch, English, 

 and French East India Companies about 1673. 



Its beautiful whiteness, its thinness, its translucency, 

 its close vitreous fracture, apart from, and also in 

 conjunction with, its decoration, at once appealed to 

 and obtained the admiration and emulation of the 

 Europeans. 



The story of the struggle in the attempt tp repro- 

 duce it is not within the scope of this paper, but 

 suffice it to say that it was accomplished in Germany 

 by Bottcher about 1706-18, and in England by Cook- 

 worthy, of Plymouth, about 1767. 



The one factory continued for the reason that not 

 only were the products excellent, but the financial suc- 

 cess was not the main object, while the other had to 

 bear its own losses, and though there was considerable 

 promise of success, the financial aspect of the under- 

 taking was a complete failure. It is well, then, at the 

 outset to note that we do not owe the origin of the 

 porcelain to the Continental potters, but to the Chinese. 



1 Abridged from a paper read nt the annual meeting of the Suciety of 

 Chemical Industry, July 18-20, by Mr. Henry Watkin. 



NO. 2502, VOL. 100] 



Chinese porcelain being at that tipie the only trans- 

 lucent pottery in existence, there can be no wonder 

 about the admiration it called forth. 



It cannot be surprising, then, that the English 

 potters were very anxious to produce such a body, and 

 if that object could be attained, the means by which 

 it was achieved were secondary matters, and we find 

 that instead of continuing the manufacture of hard- 

 paste porcelain, they produced, about the end of the 

 eighteenth century, (i) a beautiful white earthenware 

 which for generations secured the market of the world, 

 and made it possible to replace almost all other pottery 

 for domestic purposes; (2) a translucent white porcelain 

 similar to the Chinese, by the use of other materials 

 and methods, equally beautiful, which for more than 

 a century has held its own amongst all other porce- 

 lain productions, and is generally known as bone china. 

 The ceramic productions of the world as regards 

 their bodies or paste, apart altogether from decorative 

 effects, vary from goods made from the coarsest to the 

 finest clays, through almost every variety of texture, by 

 admixture of the natural clay with other materials, 

 such as sand, flint, barytes, felspathic rock, etc. From 

 these materials were produced at one end of the scale 

 the cinerary urns of our great ancestors, and, at the 

 other end, the excellent hard-paste porcelain which we 

 are considering to-day. 



The marvellous difference in the productions of the 

 various peoples of the world may probably be explained 

 by the general assertion that the potters have from 

 the very earliest times worked with the materials they 

 had at hand. The cinerary urns of the ancient Britons 

 were made from natural clays. 



The Staffordshire potters used, at first, natural clays» 

 found cropping up simultaneously with the coal, and 

 afterwards improved the colour and texture of the 

 product by the addition of, first, fireclay, then Devon 

 and Cornish clay, and calcined flint. Messrs. Eler 

 Bros, used the red marl of the Burslem district for 

 their fine red ware. Bottcher, of Germany, at first 

 made red ware from local clays, etc., and afterwards 

 porcelain from the white clays or kaolin, and pegma- 

 tite. 



The Chinese for centuries had been working with 

 their natural materials, kaolin and petuntze, and from 

 these produced their fine porcelain. Some of these 

 various clays naturally required a much greater heat 

 than others to produce hard vitreous bodies. 



These varying conditions with regard to materials 

 to the hand of the potter, when means of communica- 

 tion were so restricted, necessarily, involved very varied 

 methods of manufacture. The materials differing so 

 essentially from each other naturally required very 

 varving degrees of heat necessary to bring to maturity. 

 The kaolin and petuntze used by the Chinese would 

 require a much higher temperature to mature than 

 the clays, etc., used in other countries at the time. 

 The exact temperature would not be found at once, 

 and in working out the same an observant potter could 

 not fail to notice the changes taking place in the fired 

 material in regard to vitrification, translucency, and 

 finally distortion at the various temperatures. Thus in 

 all probability, without any more scientific knowledge 

 whatever than careful observation, the fine product 

 of that time would be produced which even now 

 (centuries later) is the object of our research. 



While the Chinese were for centuries making the 

 most suitable material in the world for chemical labora- 

 tory ware, they had no use for such, and consequently 

 did not make it. It was only with the advance of 

 scientific chemical knowledge in Europe that the need 

 was felt for the various porcelain accessories that were 

 then called into use. 



It is not surprising, therefore, that Germany and 

 France, having continued making the Chinese type of 



