266 



NATURE 



[July i8, 1907 



the homology- of the muscles of the body wall, and the 

 retrograde nature of the appendix verinilormis. These, 

 however, are all contentious matters, wliich the author 

 purposely has left undiscussed, preferring- evidently to 

 state the older view until the truth of the newer has 

 been more firmly established. A. K. 



rUE PRIXCIPLES AND PRACTICE OF FOOD 

 PRESERVING. 



Les Industries de la Conservation des Aliments. By 

 X. Rocques. Pp. xi + 506. (Paris : Gauthier-Villars, 

 1906.) Price 15 francs. 



A/I ^^OC'Q'^ES'S aim in writing the present work 



■1- ' -1 • has been to explain, for the benefit of manu- 

 facturers and others, the scientific principles upon 

 which the preservation of foodstuffs is based. 



At first sight it is somewhat curious that in dealing 

 with the problems of food-preservation no large 

 measure of success should have been met with until 

 comparatively recent times. To retain the fruits of 

 the earth against periods of scarcity must always 

 have been a desirable object. Hence such operations 

 as the garnering of grain and the drying and salting 

 of flesh were practised ages ago ; but afterwards 

 there was a gap of many centuries — one might almost 

 say from prehistoric times until yesterday — during 

 which no considerable advance was made in devising 

 means of preventing the progress of decay. It was a 

 question of the infinitely little. Against club or sword 

 of human despoilers a man might match club or 

 sword in defence of his store of foodstuffs, but he was 

 very nearly powerless against the microscopic agents 

 of putrefactive change. 



Nevertheless, in a groping, tentative sort of way, 

 some steps were beginning to be made during the 

 eighteenth century. On the theoretical side Van 

 Helmont, Boyle, Becher, Pringle, Macbride, Black, 

 and others studied the allied questions of fermentation 

 and putrefaction, whilst Lavoisier gave the first 

 touches of quantitative exactitude to such inquiries by 

 his experiments upon the alcoholic fermentation cf 

 sugar. On the practical side Gaefer and Eisen tested 

 the possibility of preserving vegetables and fruits by 

 desiccation. Then in the early part of last century 

 came Appert, who practised what is essentially the 

 process of sterilisation employed at the present day 

 on an immense scale in the preservation of every sort 

 of comestible. But it was only with the victory of 

 Pasteur in his famous controversy with Lieblg that 

 the true nature of fermentative and putrefactive 

 change became clear. It was the micro-organism, and 

 not the air (per se), nor spontaneous generation, nor 

 chemical instability, that was responsible for the 

 decay of organic tissues. Henceforward the steps 

 become firm. It is now the aim of all preservative 

 processes to prevent the development of the micro- 

 organism, whether by exclusion of its presence, or by 

 its destruction, or by the inhibition of its growth. 

 Hence it is that either heat or cold may be used for 

 the required purpose : canned peaches are edible be- 

 cause the putrefactive organisms had been destroyed 

 by heating; ice-embedded mastodons, ages after their 

 death, have furnished well-preserved carcasses because 

 NO. 1968, VOL ;6] 



the development of micro-organisms has been inhibited 

 by cold. 



After touching upon these and other points in an 

 interesting historical sketch, the author deals, shortly 

 but comprehensively, with the phenomena and pro- 

 ducts of putrefactive change in alimentary substances. 

 He passes then to the consideration of the practical 

 processes employed in preventing these changes. 

 Preservation by means pf heat is first described. To 

 give an idea of the general plan of the book we will 

 outline this section. First comes a sketch of the de- 

 velopment of the industry, with notes of localities, 

 products, and some statistics of production — not very 

 recent, by the bye — then the general technique is 

 described, including the manufacture of tins and 

 bottles, and the different methods of closing and 

 sterilising these vessels after they are filled. After- 

 wards the various classes of foods — vegetables, fruits, 

 meat, fish, and milk — are dealt with in detail, the 

 quantity of material, preliminary treatment, and time 

 of sterilisation being given where necessary for 

 each individual article. Numerous illustrations of 

 machinery and operations elucidate the text. 



This thorough and practical style of treatment is 

 continued in the remaining sections of the book, 

 dealing respectively with preservation by means of 

 cold, by desiccation, and by the use of antiseptics. 

 JVI. Rocques laments the fact that France has lagged 

 behind other countries in the use of cold storage, 

 which in the opinion of M. Muntz is the method 

 having the greatest future. In connection with this 

 an interesting parallel may be noted. Just as Lister's 

 antiseptic surgery has been largely replaced by aseptic 

 processes, so in the case of foodstuffs sterilisation by 

 heat is being to a considerable extent obviated by the 

 practical asepsis of refrigeration. 



.We can cordially endorse the closing words of M. 

 Brouardel's preface : M. Rocques has written a good 

 book and done a good deed at the same time, since 

 in all probability the health of his fellow-men 

 will benefit from using the information he summarises 

 and applying the principles he explains. 



C. SiMMONDS. 



THE THEORY OF PLANT BREEDING. 

 Le Transformismc appliqui a V Agriculture. By 

 Prof. J. Costantin. Pp. 300. (Paris : Alcan, 1906.) 

 Price 6 francs. 



BY " transformism " Prof. Costantin understands 

 the passage from one species to another or the 

 creation of new species — Lamarckianism or Darwinism 

 in contradistinction to the older theories of men like 

 Jordan concerning the absolute fixity of species. The 

 book in the main deals with plants, and consists of a 

 general discussion of the meaning of a species and of 

 such phenomena as garden varieties, bud sports, and 

 graft hybrids, the effects of climate and soil on type, 

 together with a summary of the work of de Vries on 

 mutations and of Nilsson and the Svalof station on 

 the improvement of cereals. It is a difficult and com- 

 plex country, and as so much of the progress of agri- 

 culture must depend on the creation of improved 

 varieties, the importance of a survey of the known 



