346 Analysis of Scientific Books and Memoirs. 



a membrane forming the coat of his boyau or mass of cylindrical form 

 ejected from the grain of pollen. 



I reserve, however, my observations on these and several other topics 

 connected with the subject of the present inquiry for the more detailed 

 account, which it is my intention to give. 



July 30, 1828. 



II. — Transactions of the Royal Society of Edinburgh, Vol. xi. First 

 Part, pp. 234. 9 Plates. 



This volume, of which we propose to give a brief analysis, contains four, 

 teen papers on the subjects* of Mineralogy, Geology, Optics, Chemistry, 

 Botany, and the Mechanical Arts. 



1. Description of Sternbergiie. By W. Haidinger, Esq. — A very co- 

 pious abstract of this paper has already been published by Mr Haidinger 

 in this Journal, vol. vii. or No. xiv. p. 242 — 247. 



2. Description of some remarkable effects of unequal refractidn. By the 

 Rev. W. Scoresby. — An abstract of this paper we have already given in 

 vol. vi. No. xii. p. 213, 



3. On a new combustible gas. By Dr Thomas Thomson. — The com- 

 position of this gas we have already given in No. xiii. p. 182. 



The gas is obtained by the following process : — Put into a flask a mixture 

 of 14 oz. of muriatic acid, \ oz. of the nitric acid of commerce, and \ oz. of 

 pyroxylic spirit, all by measure. By means of a perforated cork insert very 

 tightly a bent glass-tube into the mouth of the flask. Heat the mixture 

 over a spirit lamp till it begin to effervesce, and till the colour of the li- 

 quid changes to red. The flask must then be withdrawn, and the extre- 

 mity of the bent tube plunged into a mercurial trough. The gas issues in 

 torrents for five or six minutes, and may be collected in any quantity, in 

 glass jars, previously filled with mercury, and inverted on the trough. 

 From the quantity of materials stated above, at least 200 cubic inches of the 

 gas are extricated. 



The gas, as it comes over, acts with considerable energy on the mercury; 

 both calomel and corrosive sublimate being formed in abundance. But 

 this is owing to the presence of some chlorine, with which the gas, as it is- 

 sues from the flask is mixed. For when we transfer the gas into a clean 

 jar, it may be left for any length of time on the trough, without acting in 

 the least on the mercury, or changing its volume. 



The gas thus obtained possesses the following characters : — 



1. It is transparent and colourless, and has the mechanical properties of 

 common air. 



2. Its smell is exceedingly pungent and disagreeable ; but quite peculiar. 

 It acts with considerable energy upon the eyes and nose, occasioning a flow 

 of tears, and exciting considerable pain in the eyes. 



3. It burns with a lively bluish-white flame. 



