2i8 THE PKESERVATION OF MEAT, ETC. 



PIORKOWSKT (I.) arrived at a similar conclusion with regard to 

 typhus bacilli. On this account none but clean chaff, free from 

 pathogenic organisms, should be used for packing eggs. 



Bacteria are not to blame in all cases where eggs become 

 spoiled during storage, but sometimes higher fungi (Eumycetes) 

 come into play, penetrating the shell and growing freely in the 

 interior. Further particulars on this point will be found in the 

 second volume, in the chapter dealing with Hormodendron clado- 

 sporioides. 



133. Desiccating and Preserving 1 Vegetables 

 and Fruit. 



In contradiction of the erroneous assumptions of M. GALIPPE 

 (I.) and H. BERNHEIM (II.), it has been shown by E. LAURENT 

 (III.), A. FERNBACH (I.), and H. BUCHNER (VIII.) that apart 

 from the exceptions to be considered in Chapter xxxiii. the cells 

 and cellular tissues of the higher plants are, whilst in a healthy con- 

 dition, free from fungi. In the preservation of vegetable food- 

 stuffs, it is, therefore, merely a question of the destruction, or 

 restriction of development, of the germs of extraneous origin 

 inhabiting the surface. The oldest process for attaining this 

 object is that of drying, and this is practised more particularly 

 on certain fruits. In warmer regions the rays of the sun suffice, 

 e.g. in the case of raisins and figs, but in colder climes recourse 

 must be had to artificial warmth, and, consequently, so-called 

 kilns or drying ovens are employed, wherein hot air at a tem- 

 perature of 6o-65 C. is allowed to stream over the fruit. 

 American desiccated apples and Bosnian and Servian prunes are 

 prepared in this way. A description of the individual systems of 

 kilns for this purpose cannot be entered upon here. The dried 

 fruit still contains a considerable proportion of moisture (some 

 30 per cent.) and at least the same amount of sugar : about 30 

 per cent, in the case of pears, some 40 per cent, in apples and 

 damsons, 50 per cent, in figs, and 60 per cent, in raisins. From 

 i to 3 per cent, of free acid is also present. Only some of the 

 organisms present on the fruit are killed by drying, but the 

 development and decomposing action of the rest are checked by 

 the plasmolytic influence of the high sugar content. The putre- 

 factive bacteria also suffer through the action of the free acid 

 present. Sundry vegetables, especially those employed for Julienne 

 soup, are preserved by drying, for which purpose they are cut into 

 small pieces, and exposed in special ovens to a hot air temperature 

 of 5o-6o C. Not infrequently they are then, in accordance 

 with a proposal made by Masson, subjected to hydraulic pressure, 

 compressed vegetables being thereby produced. 



Drying is a comparatively inexpensive operation, but cannot 

 be resorted to in every case, since many kinds of fruit and vege- 



