Oct. 14, 1880] 



NATURE 



561 



seem to have a fair share allotted to them, and the same 

 is also the case in the courses for the senior scholarships 

 and honours — which latter cannot be competed for until 

 the end of one j-ear after the candidate takes his B.A. 

 degree. A Bachelor of Arts obtaining honours can have 

 ■>--- AT 4 deeree without special examination : all others 

 have to pass an m . _.: ^;^^ ' 



It is probable that for some time to conic m^i^ ..ti, t. . 

 great differences of opinion as to how the natural sciences 

 should be taught and examined in in our universities. 

 Some incline to limit the courses in botany and zoology, 

 and to require a good sound knowledge of the prescribed 

 work ; others imagine that the effect of limiting a course 

 is to produce a specialist, which, they argue, is to spoil a 

 student ; but the mean appears to us to be not so hard to 

 find. A sound general knowledge of development and of 

 physiology might certainly be demanded of all students, 

 and the field of biology being too large for any human 

 being to work over, the student might, as to details of 

 structure, &c., be limited to the study of some defined 

 class. It is in this direction evidently that Prof Hutton 

 has framed the schedule of zoology and botany, a 

 schedule which, while we acknowledge it to be excellent 

 from a general point of view, is, we are firmly persuaded, 

 longer and more profound than is expedient in a new 

 country, where the teaching power is not great. We are 

 fully aware that there is a tendency in classical and 

 mathematical teachers to believe that the study of natural 

 science is something quite easy ; but those able to judge 

 have long agreed that not only does this study call for all 

 the best talents, but that the student too often approaches 

 it long after the impressionable period of his life : a little 

 Latin, perhaps less Greek, a schoolboy knows ; arithmetic, 

 algebra, and geometry he is fairly familiar with ; but the 

 natural sciences and the how he lives, moves, and has his 

 being, of these he is fain to exclaim. But who arc ye .' 

 The professors of natural science must bide their time ; 

 it is no doubt coming, for biology is now somewhat 

 taught in our schools, and may be will be taught on the 

 mother's knee ; but in the meanwhile let them not exact 

 too much from candidates for B.A. degrees or honours ; 

 let them progress surely, even though they be accused of 

 progressing slowly. As to the New Zealand University, 

 we shall follow its progress with pleasure, and trust it 

 may soon fulfil the great expectations that we have of it. 



DOCTORED WINES 

 T^HE French Government have just passed a most 

 •^ salutary measure, which will have for efifect the 

 diminution, if not the complete suppression, of the pro- 

 cess known as pldtragc, now become an almost constant 

 custom through most of the wine districts of France, and 

 which, from having at first been performed on a very 

 moderate scale, has lately enormously increased, till it 

 has developed into a crying abuse. The pldtrage is 

 carried on during the fermentation, and consists in merely 

 sprinkling the grapes, as successive baskets of them are 

 emptied into the fermentation vats, with plaster of Paris 

 — calcium sulphate — (French platre), mineralogically 

 known as gypsum, or selenite, in fine powder. Now the 

 grape-juice contains several salts of potash, among 

 which the most abundant are the tartrate and bi-tartrate, 

 and these decompose when placed in contact with the 

 calcium sulphate, forming calcium tartrate — an insoluble 

 salt — and potassium sulphate. 



In the case of potassium bi-tartrate, potassium bi-sul- 

 phate is formed. Now besides the salts of potash above 

 named, tlie juice of the grape contains grape-sugar, a 

 nitrogenous fermenting principle and an astringent prin- 

 ciple — to which latter new red wines owe much of their 

 harshness — and also a red colouring-matter, with which 

 the astringent principle is intimately associated. The 

 fermentation splits up the grape-sugar, as it is well 



known, into carbonic acid, which escapes with efierves- 

 cence, and alcohol, which remains dissolved. In pure 

 undoctored wines, in proportion to the development of 

 alcoholic strength, and as the wine by age tends to 

 become more acid, potassium bi-tartrate separates as a 

 crystalline precipitate, forming the chief constituent of 

 the deposit in the casks known as kes, or, when it forms 

 "■" ilo'f\!^^.c^l55^..^!.''^« "-"{'; ,. , . , 

 as we have explained, "intlmaT^=V5i.ftSiS<^ S^^J'^'^; 

 colouring-matter, seems to be held more or less in solu" 

 tion by the tartrates, and as these subside with age the 

 wine grows less harsh, losing at the same time much of 

 its colour, and is said to ripen or grow mellow. As the 

 astringent principle however disappears, the wine, if it 

 be one of the weaker French wines, tends to run to the 

 acetous fermentation, and this is why we frequently find 

 a wine become sour and unpalatable shortly after it has 

 niellowed with age and arrived at its maximum of perfec- 

 tion. Many a bin of valuable claret or Burgundy has 

 thus suddenly surprised and disappointed its possessor, 

 changing in the short space of a few months from fine 

 mellow wine to undrinkable vinegar. 



Now, as stated above, calcium sulphate {pldtre) 

 decomposes the potassium tartrates, and by withdraw- 

 ing them and substituting the potassium sulphate, 

 tends to prevent much of the colouring and astringent 

 matter from passing into solution, so that this so-called 

 platragc is nothing more than a means employed by 

 the Bordelais and Burgundians for giving to their wines 

 a fictitious effect of age, and they naturally defend a prac- 

 tice which enables them to bring their wines sooner into 

 the market, economising their outlay in casks, and diminish- 

 ing the chances of loss entailed by keeping a large stock 

 of wine on hand. Further the process lends itself to fraud, 

 permitting the wine merchants of Bordeaux and Bur- 

 gundy to import the strong harsh wines of the north of 

 Spain and the south-east of France, which, when blended 

 with the small, poorer wines of the hill-districts of their 

 own country, and then being platres (that is agitated 

 with powdered calcium sulphate), become mild and palat- 

 able. Thousands of hogsheads of wines thus blended 

 and doctored are annually sold, and too often at the high 

 rates commanded by pure vintage Avines. Under the 

 provisions of the new act no wine is allowed to be 

 brought into commerce if it contains over two grammes 

 of potassium sulphate per litre. Even this proportion is 

 too large, pldtrage should be entirely prohibited ; but 

 when we consider that wines are now often sold with 

 five or six grammes of this salt to the litre, it was time 

 indeed that some measures should be taken. The 

 merchants defend themselves on the basis of the practice 

 being innocuous, and that while it promotes the keeping 

 qualities of the wine, even four grammes of potassium 

 sulphate could do no harm. It is the greatest possible 

 mistake to fancy that platragc makes wine keep ; for, no 

 the contrary, it withdraws from it the astringent principle, 

 a most potent means of its preservation. For a Bordeau.x 

 merchant to contend that forty grains of potassium sul- 

 phate to the pint of wine is not or cannot be unwholesome, 

 is a thesis which may be agreeable to his pocket, but 

 certainly ought to be discouraged, for, to say the least, it 

 would surely be prejudicial to the stomachs of delicate or 

 dyspeptic consumers. Not very many years since a case 

 occurred of actual death by poisoning from the admini- 

 stration of a comparatively small dose of potassium sul- 

 phate, and this salt is well known in medicine as a 

 drastic and dangerous purgative. We should then be 

 most sincerely grateful to the French Minister of Com- 

 merce for the prudent forethought with which he has 

 protected the consumers of French wines from a practice 

 which had grown into a crying abuse, and for giving us 

 one more guarantee for the purity of these wines, justly 

 ranked as the most esteemed that the world produces. 



