October 27, 19 10] 



NATURE 



525 



NATURALISTS' NOTES FROM THE OLD 



SPANISH MAIN. 



Our Search for a Wilderness. An account of two 



ornithological expeditions to Venezuela and to 



British Guiana. By Mary Blair Beebe and C. 



William Beebe. Pp. xix + 408. (New York : Henry 



Holt and Co.; London: Constable and Co., Ltd., 



igio.) Price 10s. 6d. net. 

 A FEW years ago the authors wrote a pleasant 

 -il- little book, "Two Bird-lovers in Mexico." The 

 present " Search for a \\"ilderness " did not prove 

 difficult, because they found one in the mangrove 

 swamps on the old Spanish main, opposite the island 

 of Trinidad. They hired a little sloop, and cruised 

 about on the San Juan river, which falls into the 

 Gulf of Parian. The mud-flats teemed with life, and 

 after nightfall arose the many quaint and mysterious 

 sounds of the tropical jungle. For one of these 

 sounds, a muffled choking, they found an unexpectedly 

 simple explanation. The anaconda makes its lair in 

 a hole in the bank at the waters" edge. When the 

 rising or falling tide laps into or out of the vacated 

 niudhole, a big bubble of air frees itself with a sudden 

 gasping sob. Further up the river they visited L;i 

 Brea, the strange lake of pitch in the midst of a region 

 of primeval forest. 



Whilst on this visit to Venezuela the collecting of 

 birds was incidental; they went in the spring of 1909 

 to British Guiana, accompanied by an assistant, to 

 collect birds in earnest ; but Mr. Beebe is certainly not 

 a destructive ornithologist. His party killed only 

 .about one hundred specimens, and these because of 

 some special interest, and there occurs the following 

 passage which deserves quoting. " We were glad to 

 find that the most diflicult privilege to obtain is a 

 permit to collect birds, and the very stringent laws in 

 this respect are an honour to the Governor (Sir 

 Frederick Hodgson, K.C.^LG.), and his colonial 

 officials. Thank^i to the absence of the plume and 

 general milliner hunter, the game hog, and the whole- 

 sale collector, birds are abundant and tame." 



From Georgetown as their centre they made several 

 trips. Hospitably entertained, and being spared all 

 the usual annoyances of transportation, thev visited, 

 by launch, the Hoorie gold mines in the north-western 

 corner of the colony, an excellent place for studying 

 the ways of its wild inhabitants. Thence they made 

 their way back to the capital, threading little-known 

 rivers and creeks in a canoe, and for five davs they 

 were paddled, portaged, towed, and pushed through 

 a wonderland abounding in beautiful birds, butter- 

 flies, and orchids, and they were made welcome for 

 the night at little isolated Indian missions. 



Next followed a trip up the Essequibo and one of 

 its tributaries to the .A.remu mine. In these waters 

 they saw- the little freshwater flying fish, CarnegieUa 

 spii^aliis, which, however, " did not leav^e the surface 

 entirely, but skimmed steadily along in a straight 

 line, with the tip of the deep keel of the abdomen just 

 cutting the surface." ' The travellers were keen and 

 lucky enough to make many interesting observations, 

 which they have recorded in a pleasantlv easy stvle, 

 NO. 2139, VOL. 84] 



illustrated with numerous good photographs of scenery 

 and scenes of many creatures, from man to insects. 

 .\ narrative sparkling with incidents needs no froth 

 like the following : — " Most curious of all were the 

 Loricates or armoured catfish, with a double row of 

 large overlapping scales enclosing their body from 

 head to tail. Like the Hoatzin among the birds, these 

 fish are strange relics of the past, preserved almost 

 unchanged from the ancient fossil Devonian fauna." 

 Relics of the past, by all means, but what have the 

 Siluroid Teleostean fishes to do with the Devonian 

 epoch ? 



.\ visit to the savannahs and lagoons of the .\bary 

 river, with its abundance of bird life, for instance, 

 large colonies of the quaint Hoatzin, was cut short by 

 a broken wrist suffered by the lad}-. We wish them 

 many more such pleasant trips, and may they not be 

 undeceived in their optimistic opinion as to " the falsitv 

 of most of the universal slanders on a tropical 

 climate." 



GRAPHICAL CHEMISTRY. 

 Leitfaden der graphischen Chemie. By Dr. R. 

 Kremann. Pp. 36 + 5 modellc. (Berlin: Verlag 

 von Gebruder Borntraeger, 1910.) Price 6.bo 

 marks. 



IN view of the importance of a knowledge of the 

 equilibrium relationships which are involved w-hen 

 two or more substances are brought together in 

 different quantities under different conditions of ten-i- 

 perature and pressure, and of the rapid progress 

 which has been made in recent years in the study of 

 more complicated cases of such equilibria, it is essen- 

 tial that the student of physical chemistry should be 

 faniiliar with the various methods which are used for 

 the graphic representation of experimental results. 



There can be no doubt that the interpretation of 

 the space models, which are employed w-ith great ad- 

 vantage to depict the equilibrium relationships of 

 ternary and quaternary systems, offer considerable diffi- 

 culties to those who are not familiar with the sub- 

 ject. This is the author's experience, and the issue 

 of a series of five adjustable cardboard models, with 

 an explanatory guide, is intended to facilitate the 

 acquirement of a know-ledge of the rudiments of 

 graphical chemistry. 



The cardboard models, which are made to scale 

 from experimental data, represent respec-dyely the 

 equilibrium relationships in the following systems — 

 (i) Silver nitrate and w-ater (2) potassium sulphide, 

 magnesium sulphate and water (3) tin, lead and bis- 

 muth (4) ammonium nitrate, water, methyl alcohol and 

 ethyl alcohol (5) water and the reciprocal pairs of salts 

 — sodium chloride + ammonium hydrogen carbonate :;:^ 

 ammonium chloride + sodium hydrogen carbonate. 



These systems afford sufficient material for an ex- 

 position of the various modes of graphic representa- 

 tion, but it is very doubtful whether prepared models 

 of this character can be of much service to the student 

 whose aim is thoroughly to understand the connection 

 betw-een the space models and the actual experimental 

 data. In the reviewer's opinion the requisite 



