ON THE PROGRESS OF SCIENCE. VII 



animal. It is not, indeed, to be anticipated that the chemist should 

 ever be able to produce, by the operations of the laboratory, the 

 arrangement of the elements in the forms of the vegetable cell or the 

 animal fibre ; but he may hope to succeed in preparing some of the 

 complex results of secretion or of chemical changes produced within 

 the living organism, changes which furnish definite crystallizable 

 compounds, such as the formiates and the acetates, and which he has 

 actually obtained by operations independent of the plant or the ani- 

 mal. Hofmann, in pursuing the chemical investigation of the remark- 

 able compound which he has termed Triethylphosphine^ has obtained 

 some very singular compound ammonias. Triethylphosphine is a body 

 which takes fire spontaneously when its vapor is mixed with oxygen, at 

 a temperature a little above that of the body. It may be regarded as 

 ammonia in which an atom of phosphorus has taken the place of nitro- 

 gen, and in which the place of each of the three atoms of hydrogen in 

 ammonia is supplied by ethyl, the peculiar hydrocarbon of ordinary 

 alcohol. From this singular base Hofmann has succeeded in procuring 

 other coupled bases, which, though they do not correspond to any of 

 the natural alkalies of the vegetable kingdom, such as morphia, quinia, 

 or strychnia, yet throw some light upon the mode in which complex 

 bodies more or less resembling them have been formed. 



" The bearing of some recent geological discoveries on the great 

 question of the high antiquity of Man was brought before your notice 

 at your last meeting by Sir Charles Lyell. Since that tune many 

 French and English naturalists have visited the valley of the Somme 

 in Picardy, and confirmed the opinion originally published by M. 

 Boucher de Perthes, in 1847, and afterwards confirmed by Mr. Prest- 

 wich, Sir C. Lyell, and other geologists, from personal examination of 

 that region. It appears that the position of the rude flint-implements, 

 which are unequivocally of human workmanship, is such, at Abbeville 

 and Amiens, as to show that they are as ancient as a great mass of 

 gravel which fills the lower parts of the valley between those two 

 cities, extending above and below them. This gravel is an ancient 

 fluviatile alluvium by no means confined to the lowest depressions 

 (where extensive and deep peat-mosses now exist), but is sometimes 

 also seen covering the slopes of the boundary hills of chalk at eleva- 

 tions of eighty or one hundred feet above the level of the Somme. 

 Changes, therefore, in the physical geography of the country, compris- 

 ing both the filling up with sediment and drift, and the partial reexca- 

 vation of the valley, have happened since old river-beds were, at some 

 former period, the receptacles of the worked flints. The number of 

 these last, already computed at above fourteen hundred in an area of 

 fourteen miles in length and half a mile in breadth, has afforded to a 

 succession of visitors abundant opportunities of verifying the true 

 geological position of the implements. 



" The old alluvium, whether at higher or lower levels, consists not 



