November 17, 1904] 



NA TURE 



51 



brous machinery has had to be devised. To summarise 

 and explain this machinery is the aim of the work 

 under notice. In the main it is intended for the food 

 analyst, and the author's idea has been to give this 

 official some information, not only on the subject of 

 food-analysis, but also on various collateral matters 

 with which he is brought into contact. Thus there are 

 sections discussing the equipment of the laboratory, 

 the storage of samples, legal precautions, the duties' 

 of the food inspector, and certain processes of food 

 manufacture. 



All the ordinary foodstuffs are dealt with, a chapter 

 being allotted to each group of allied products, such 

 as cereals, spices, alcoholic beverages, and so on. The 

 descriptions are written clearly ; an excellent selection 

 of the salient facts and the best methods of examin- 

 ation has been made ; and to each division an extensive 

 bibliography is appended. Microscope work is a 

 special feature, and the volume is enriched by a series 

 of forty plates, containing about four times as many 

 photomicrographs of the principal vegetable and 

 animal structures met with in the examination of 

 foods. 



The chief criticism to offer on the book is that the 

 treatment of so much material in one volume — even 

 one of eight hundred pages — must necessarily be in 

 the nature of a summary. Hence in many instances 

 the information, though sufficient for routine work, 

 is not full enough to be of much value when cases of 

 real difficulty arise. 



One notes several examples of careless transcription 

 in looking through the work. On p. 441 the so-called 

 " Koettstorfer's equivalent " for butter-fat is given a 

 maximum value of 241 and a minimum of 253. It 

 might be guessed that these two numbers have been 

 transposed ; but on the next page the value of the 

 constant in question is given as 224. The author has, 

 in fact, failed to distinguish between the " equivalent " 

 and the " value " of the saponification experiment. 

 In the table on p. 441 the values of the insoluble acids 

 for oleomargarine are transposed ; the specific gravity 

 has no temperature of reference ; and a faulty arrange- 

 ment of the table makes it appear that butter-fat and 

 margarine possess, somehow, a maximum and a 

 minimum temperature ; whilst in the data for edible 

 oils and fats on p. 380 the limiting values are again 

 transposed. 



Nevertheless, it would be unfair to judge the book 

 by these slips. It contains a large amount of inform- 

 ation and, though written more particularly from the 

 American point of view, will be found a useful con- 

 spectus of the whole field of food control. 



C. SiMMONDS. 



TH£ TRANSPIRATION OF PLANTS. 

 Die Transpiration der Pflanzen. Eine Physiologische 

 Monographie von Dr. Alfred Burgerstein, A. O. 

 Universitatsprofessor in VVien. Pp. ,x + 283. (Jena : 

 Gustav Fischer, 1904.) Price 7.50 marks. 



THIS book is a classified analysis of the published 

 work on transpiration from the time of Hales 

 onward, with a running criticism by the author, who 

 NO. 1829, VOL. 71] 



is well known to have attended to the subject for many 

 years. 



The amount of contradictory evidence is remarkable. 

 In the case of the earlier experimenters, with more or 

 less faulty methods, this is not surprising; but the 

 same thing strikes one in many modern instances. 

 The question of the amount of transpiration in moist 

 tropical regions, as compared with Europe, is a case 

 in point. Another instance is what the author de- 

 scribes as a " seven years' war " (1884-1891) between 

 VVille and Lundstrbm as to the absorption of water 

 by the aerial parts of plants. Other disputed points 

 are the effect of salt solutions supplied to the tran- 

 spiring plants, and the influence of varying amounts 

 of CO„ in the atmosphere ; and many other cases might 

 be cited. 



The relation of plants to water, though a subject of 

 primary importance, is still to a great extent in the 

 elementary stage of inquiry. A large number of the 

 statements quoted by Burgerstein are little more than 

 disconnected facts, and, in spite of the interesting book 

 he has made of them, they still seem to us to await 

 a somewhat different treatment. 



The subject-matter of the book falls into two 

 classes : — (i) the loss of water-vapour considered as 

 physical phenomenon ; (2) the biological inquiry into 

 the adaptation of plants to the distribution of water 

 considered as environment. From both points of view 

 transpiration should be considered side by side with 

 assimilation and respiration, and this manner of look- 

 ing at the subject has not, in our judgment, been kept 

 sufficiently in mind by the author. The point is that 

 the same organs — the stomata — serve for gaseous ex- 

 change and for the evaporation of water. Burgerstein 

 discusses at the end of his book the question whether, 

 as some have supposed, transpiration is a necessary 

 evil. This might have been discussed from a broader 

 standpoint, and would have been in place in an earlier 

 chapter. It does not seem necessary to treat the view 

 referred to as entirely false. Plants undoubtedly have 

 to strike a balance between the possession of a free 

 stomatal connection with the atmosphere and the con- 

 sequent danger of evaporating more water than they 

 can take up from the soil. This compromise includes 

 also the value of the transpiration-stream in supply- 

 ing minerals to the aerial parts, on which Burgerstein 

 rightly lays stress. All we suggest is that the whole 

 problem, being of a fundamental character, might well 

 have been dealt with more liberally, and been given a 

 place preliminary to the details of transpiration. 



A fault in Burgerstein 's treatment of transpiration, 

 though a fault difficult to avoid, is that he does not 

 keep before the reader the fact that the condition of 

 the stomata- — ^whether open, half open, or shut — is far 

 and away more important than all the other internal 

 conditions put together. Like the rest of the world, 

 he is well aware of this, but we doubt whether the 

 uninstructed reader would here learn to think of the 

 problem in this way. To take an example, he de- 

 scribes (p. 62) how, when part of the foliage is re- 

 moved, the remaining leaves transpire more actively 

 than before. Here we want a discussion of the possible 

 effects, direct or indirect, of the operation on the 



