214 
NATURE 
[ ¥uly 8, 1886 
oleic series, we have in this chapter brief descriptions of 
glycerol (nitroglycerol and dynamite), the fatty acids from 
butyric upwards, and the acrylic series from oleic acid 
upwards. The descriptions of the acids are concisely 
given, and their occurrence, preparation, and physical 
properties briefly described. Of the chemistry of the 
higher homologues of the acids of these series but little 
is known, and the name of the acid which heads each 
paragraph is simply followed by its empirical formula. 
This treatment is all that is necessary in such a work as 
the present, but it will certainly occur to the more 
advanced chemical readers that a very wide field of inves- 
tigation is offered to those who interest themselves with 
the question of isomerism among these complicated com- 
pounds. Considering the cheapness and abundance of 
the commoner animal and vegetable oils in daily use it 
does appear somewhat remarkable that more work has 
not been bestowed upon them by scientific chemists, and 
that the information which we have concerning them 
should be almost confined to their commercial testing 
and valuation. 
Animal oils, fixed and volatile, are described in the 
second chapter, the former being divided into animal oils 
proper (butter-fat, lard, neat’s foot, tallow, &c.), fish oils | 
(cod-liver, seal, sperm, whale, &c.), and insect oils (niin, 
ant-grease, &c.). Among the volatile oils of this class we 
have bone-oil, castoreum, and civet oils (animal), and 
ambergris (fish). The third and fourth chapters are 
devoted to vegetable oils, a list of 19 drying and 23 non- 
drying oils being given. Linseed and olive oils, the most 
important members of this group, naturally claim the 
largest amount of space, and the technology of these pro- 
ducts is well treated of. The volatile vegetable oils are 
very fully dealt with, no less than 56 pages being devoted 
to their consideration. After a description of the various 
methods of extraction by distillation, solvents, &c., the 
oils themselves are described individually according to 
their vegetable sources, the botanical names of the class 
and order being followed by a descriptive list of the oils 
obtained from each group of plants. Thus under Auran- 
tiacee we have the oils of bergamot, cedrat, citron, 
lemons, limes, neroli, and orange ; under Caryophyllacee, 
cajeput and clove oils, and so forth. 
In the fifth chapter, empyreumatic, medicated, mixed, 
and perfumery oils are treated of. We give a specimen of 
the editor’s conscientiousness in his description of medi- 
cated oils:—“ EARTHWORM OIL. Syn. Oleum lumbri- 
corum(E. Ph. 1744). Washed earthworms, } |b. ; olive oil 
1} pint; white wine, 3 pint. Boil gently till the wine is 
consumed, and press and strain.” We are not informed 
what special merit is possessed by this gruesome con- 
coction, but it was no doubt applied in good faith in the 
last century. Under “mixed oils” will be found a col- 
lection of strange mixtures, some of which might have 
formed ingredients in that “charm of powerful trouble ” 
brewed by the witches in Macbeth. The familiar “nine 
oils” of the past generation of housewives, and even 
furniture oil, find place herein, together with some three 
dozen others. Chapter VI. contains an account of waxes, 
which are classed as animal, vegetable, and artificial, a 
useful method of distinguishing these substances by their 
behaviour with chloroform concluding the section. 
The seventh chapter, a somewhat 
lengthy one, is 
devoted to mineral oils, viz. those obtained by the distilla- 
tion of shales, coal, lignite, and peat, and those found 
naturally formed in various parts of the world. The 
treatment of coal-tar and the petroleum industries are 
well described, and the chapter concludes with sections 
on the storage of petroleum and the construction of petro- 
leum lamps. Oil refining is treated of in the eighth 
chapter, which is a short one—almost too short consider- 
ing the large number of processes which are now or have 
been formerly in use. The methods for refining tallow, 
wax, petroleum, and resin oil are included in this chapter, 
besides the purification and bleaching of animal and 
vegetable oils proper. 
The longest chapter in the book is the ninth, which 
extends to 109 pages, and is devoted to the important 
subject of the testing of oils. This chapter is certainly a 
good one, both for thoroughness and the arrangement of 
its contents. Thus the testing of an oil may have for its 
object, the determination of purity, the lubricating effi- 
ciency, or the illuminating value. The purity may be 
ascertained by chemical or physical tests, both of which 
methods are very fully and lucidly treated of for each 
class of oils. Among physical tests are described the 
various methods of determining the specific gravity and 
melting point, cohesion figures, &c. The descriptions of 
the latter, which are quoted from a paper by Miss Crane, 
would have been of more value if figures had been given. 
The chemical tests, qualitative and quantitative, are given 
with great completeness. A figure of Abel’s petroleum 
tester and the method of using it as prescribed by the 
Act of Parliament finds place in this section. For testing 
the lubricating value the machines of Stapfer, Thurston, 
and Bailey are described and figured; for viscosity the 
apparatus devised by Lamansky, and by Townson and 
Mercer; and for fluidity the apparatus of Bailey is also 
described and figured. The section on illuminating effi- 
ciency is not so full, and might be advantageously 
expanded in a future edition. 
Chapter X. is devoted to resins and varnishes, and the 
last chapter contains descriptions of Mills’ bromine ab- 
sorption process and Hirscholm’s method of testing 
resins. The appendix contains some useful tables of 
prices, of the amount and value of the export of seed oils 
during 1882, 1883, and 1884, and of the production of 
shale oil in the United Kingdom during the last five 
years. 
From the foregoing epitome of the contents it will be 
seen that the volume, although a small one, gives a most 
comprehensive view of the subject of which it treats, and 
the amount cf useful information which has been con- 
densed into this small compass is mainly due to the 
concise mode of treatment which the editor has adopted. 
We can certainly recommend it to those for whom it is 
written. R. MELDOLA 
HARTLAUB ON THE MANATEES 
Bettrage zur Kenntniss der Manatus-Arten. Von Dr. 
Clemens Hartlaub (Bremen). Separatabdruck a.d. 
Zoologischen Fahrbiichern, Band I. (1886.) 
ACs other interesting articles with which Dr. 
Spengel’s new zoological journal has commenced 
its career is one by Dr. Clemens Hartlaub (son of the 
a ri i, Oh nt ee a ne Cl 
