420 



NATURE 



{Sept. 19, 1872 



interior of the vessels F, F', where cold water circulates. 

 The boiling wort can be turned into the fermenting vats 

 themselves, to which the cooling tubes alluded to have 

 been added, besides covering over these vats with a tin 

 cover by hydraulic pressure, or else the boiling wort will 

 cool in a large apparatus F or f', fitted with cooling tubes 

 for the circulation of water ; then, at the moment when 

 fermentation begins, the wort is turned into the fermenting 

 vats closed by their hydraulic covers. It is even possible 

 to make the common refrigerators serve by enclosing them 

 in a vessel full of carbonic acid gas, or of air deprived of 

 germs, and even ordinary air, if the vessel is of small 

 capacity. 



" To recapitulate : — the main and altogether novel prin- 

 ciple of my process consists in the employment of vats of 

 tin or wood, into which the wort is run as hot as possible, 

 and is cooled by a current of water outside, or outside 

 and inside at once, without any evaporation, over which 

 there is absolute control ; so much is this the case that, 

 according to the terms of my patent, nothing is more 

 simple than to transport the wort without danger to the 

 greatest distances. With regard to the action of the air, 

 we can limit it at pleasure, in so far as it is no.xious, for 

 we can always annihilate the mischievous influence of 

 the germs it contains. The brewer has, moreover, the 

 control over the action of free oxygen gas, so far as it 

 consumes the aromatic or other very delicate principles. 

 Besides, my process allows the temperature to be kept 

 steadily at any height for the purpose of fertnentation. 

 In short, its advantages .are valuable for the fermentation 

 of German beer, or for mild fermentation, for we can pro- 

 ceed to the employment of ice or any other powerful 

 means of cooling during the process of fermentation. 

 There, is, however, no distinction between strong and 

 mild fermentation, except in so far as the greater or less 

 specific differences of two yeasts, strong and mild, are 

 concerned. The two yeasts can be kept equal ; the fer- 

 mentation will be accomplished in the cold vats. 



" Ere long I shall indicate how we may obtain at 

 pleasure, at all seasons, and in all places, the two yeasts 

 in a state of purity, without having recourse to those of 

 the brewer. 



" The ferment which is deposited at the bottom of 

 the vessels,' F', is of a brown colour, because it is mixed 

 with the deposit characteristic of the wort during the 

 cooling process. It will be easy to collect it almost white, 

 and without mixture, either by scraping the surface of the 

 cake which it forms at the bottom of the apparatus, or by 

 introducing at the outset into the apparatus, at the moment 

 when we place the cover on the boiling worts, circular 

 plates, attached to a bar which passes through the cover. 

 This upright bar should terminate in the quadrant of a 

 circle, round the extremities of which it can be turned, and 

 moved up or down. While the wort is cooling, the plate 

 of each apparatus will have its plane in a vertical position, 

 and thus it will remain during the first days of violent 

 fermentation. Then, when the ferment begins to settle 

 down, the plate should be gently lowered until it is hori- 

 zontal. After the product has been drawn off, a cake of 

 ferment will be found upon the plate. " 



M. Pasteur made still ano'her addition to this process, 

 which was added to his patent in January 1872. It is as 

 follows : — 



" When the yeast in one pan is spoiled from any 

 cause, it is necessary to have recourse to yeast taken 

 from another pan. It then becomes a matter of import- 

 ance to be able to prepare for one's self in any kind of 

 vessel whatever a yeast deprived of all deleterious germs. 

 I have solved this problem by discovering that the Myco- 

 drrma vi/ii can be made the nucleus of a mild yeast. It 

 can be made to develop itself in the wort of beer sheltered 

 from contact with the air. I have also discovered that the 

 fermenting principle of the grape is a mild yeast. It is 



a source to which breweries established according to my 

 process can resort." 



This addition is, in my opinion, of great importance. 

 M. Pasteur's researches will not probably end hero. Every 

 day brings with it a new idea. At all events, from this 

 time the manufacture of beer has received such valuable 

 improvements as will tend to its increased production and 

 use. The process has not yet received the sanction of 

 long experience, but it appears to have fulfilled all that 

 was expected of it. Some have asserted that M. Pasteur's 

 system involves an enormous expense. I do not believe 

 it ; experience will show these objections to be unfounded. 



After all I know very well that M. Pasteur may yet be 

 the victim of envy. It will be remembered v/hai annoy- 

 ance an enemy gave him in connection with his process 

 for improving wines. 



M. CHEVREUL 



A VERY interesting episode took place at the seance 

 ■^*- of the French Academy of Sciences of September 

 2, on the occasion of what may be regarded as the aca- 

 demic jubilee of the Dean, the famous chemist, M. 

 Chevreul. The fiftieth year of his membership does not 

 strictly occur till 1S76 ; but it is well known that he would 

 have laeen elected in 1816, had he not urged the Academy 

 to give the vacant place to .M. Proust, his compatriot, and 

 a celebrated chemist, who was old and infirm, and could 

 not afford to wait. M. Faye, as president of the Academy, 

 intimated that the members had resolved, as a token of 

 their estimate of his works, .and their regard for his per- 

 sonal character, to present the venerable Dean that day 

 with a medal, without waiting for the arrival of the formal 

 jubilee. The medal represents the features of the illus- 

 trious chemist, who bears the weight of his 86 years 

 much more lightly than many of his fellows who are 

 considerably younger than hiaiself. M. Dumas, the cele- 

 brated chemist, and permanent secretary of the Academy, 

 in an eloquent and gracefully-worded speech, recounted 

 the many valuable services rendered by M. Chevreul, who 

 modestly styles himself "le doyen des dtudiants frangais," 

 and at the same,^ tiine bore warm testimony to the per- 

 sonal character of the man. After M. Elie de Beaumont, 

 who had been a pupil of M. Chevreul, had added a few 

 words of veneration and respect for his old master, the 

 latter attempted to respond, but had simply to express 

 his inability to do so. It was in 1806 that M. Chevreul 

 published his first most important work. He was colla- 

 borator of Vanquelin : and he has just completed a 

 volume, entitled " Mdmoires de I'Acaddmie,'' a most in- 

 teresting work, which throws light upon many of the most 

 scientific questions of the day. M. Chevreul is one of 

 the most distinguished chemists of the age ; and, besides 

 being Dean of the Academy of Sciences, is Director of the 

 Museum of Natural History at the Jardin des Plantes. 

 He has chosen for his motto that beautiful maxim of 

 Malebranche, which indeed affords a true key to his life, 

 his works, and his discoveries, " Chercher toujoiirs Vin- 

 faillibiliic, sans avoir la pi-itcntioii dc I'aitciiidre jamais." 



NOTES 



It is stated, on the authority of a private telegram from Bom- 

 bay of Tuesday last, that letters from Dr. Livingstone, dated 

 July 2, 1S72, have been received at Zanzibar. He was still at 

 Unyamyembe, was well, and waiting the arrival of Stanley's 

 second expedition. 



The fourth three-yearly meeting of the French Institute will 

 take place ontlie 2nd of October, and the yearly public meet 

 ing on the 25th of October. 



