“820 
48.73 grs. of acetate of silver left 
31.49 grs. of metallic silver. 
17.24 grs. will therefore express the loss, 
due to the united weight of acetic acid and 
oxygen combined with the silver. 
Equ.of sil. 
31.49 : ; 108 ot: 
lequ. oxy. 
59—} 8 = 51, the equivalent num- 
ber of acetic acid. 
Another example will shew the method of 
calculating the number of equivalents of each 
element in the compound. 
By analysis with oxide of copper we find 
10 grs. of acetate of silver yield 
5.277 grs. of carbonic acid and 
1.620 grs. of water 
and calculating from the 
previous experiment, . 6.462 silver, 
this is equivalent to .... 1.439 carbon 
0.180 hydrogen 
17.24 : + (=59) 
The deficiency is .......- 1.919 oxygen. 
10.000 
Then by proportion— 
Silv. oe te § Carb. C. 
6.462 : 108 :: 01.439: 2 (= 24), or 4 
Hydrog. H. 
6.462 : 108 ; 0480 :a(= 3),0r3 
Oxygen oO. 
6.462 : 108 ; 1.919 : x (= 32), or 4 
Total.. = 59 
deduct 1 equivalent of oxygen 8 
C4 
t stor 3 
Sometimes no compound with silver can be 
obtained, and a salt of lead is then, if prac- 
ticable, substituted for it. The residue, how- 
ever, in this case does not consist entirely of 
metallic lead, neither is it all oxide of lead. 
It is carefully weighed, treated with acetic acid 
in the crucible itself; the oxide of lead is thus 
dissolved and washed away. When the con- 
tents of the crucible have been carefully dried, 
a second weighing gives the quantity of me- 
tallic lead, whilst the loss furnishes that of the 
oxide. From the metal we calculate the quan- 
tity of oxide to which it is equivalent; this 
added to the portion dissolved by acetic acid 
furnishes the whole quantity of oxide con- 
tained in the compound :—a calculation similar 
to that employed for the silver salt, then sup- 
plies us with the means of determining the 
equivalent number of the body analysed. This 
method is not quite so accurate as the preceding; 
it involves more manipulation, and the com- 
pounds of lead are — to undergo slight loss 
by volatilization at a high temperature. 
It would here be out of place to enter into 
detail into the methods of checking the cor- 
rectness of an analysis in its various parts. 
Upon this point the reader is referred for in- 
formation to Liebig’s Introduction to Organic 
Analysis. The subject is an important one, 
and we obtain the equivalent 
of anhydrous acetic acid... 
ORGANIC ANALYSIS. 
face of the ground, or raise 
and by no means sufficiently attended to by the 
majority of those who devote themselves to — 
analytical researches of this description. 
The number of authors who have written — 
upon the methods of analysis is great; 
a3 their instructions are hae sate eden 
tached papers, scattered through the various” 
scientific periodicals than in systematic treatises, 
The works which may be consulted with espe- 
cial advantage on proximate analysis are Berze- 
lius’s Lehrbuch ber Chemie, third German — 
edition, translated by Wohler, 10 vols. 8vo.; the 
fourth edition of Prout’s Treatise on Diseases 
of the Stomach and Urinary Organs, and hi 
papers in the Medico-Chirurgical and Philoso- 
phical Transactions; G.O. Rees on the Analysi 
of Blood and Urine; Lecanu, Ann. de Chimie 
xlviii., and various papers on the blood ; Simon, 
Handbuch der augewandten Medizinischen 
Chemie, 2 vols. 8vo. 1840-42; one of the 
most recent and best treatises on animal che- 
mistry, full of laborious and careful analyses 
with copious and accurate directions for thei 
rformance. This work is now being trans. 
ated into English. < 
For directions for analysing the inorgat 
constituents of organized compounds the reade 
is referred in particular to Rose’s Analytic 
Chemistry, either the fourth German edition, « 
the Engiish translation of the first edition b 
Griffin. : 
Ample instructions for the ultimate an: 
of organic substances are furnished in Liebi 
Organic Analysis, translated by Gregory, a 
forming one of the series of works publish 
in Griftin’s Scientific Miscellany, and in t 
fifth volume of Dumas’ Traité de Che 
Appliquée aux Arts, as well as in the volun 
of Berzelius already referred to. 
A valuable treatise has recently been pi 
lished in German by Vogel, jun. on the | 
plication of the microscope to the field” 
animal organic chemistry—*“ Anleitung 2 
Gebrauche des Mikroskops zur Zoochemise 
Analyse und zur Mikroscopisch-chemischi 
untersuchung uberhaupt.” f. 
( W. A. Miller. 
OSSEOUS SYSTEM. (Compara 
Anatomy.)—One of the most striking — 
distinctive characters peculiar to the hig 
grades of animal existences, the VerTEBR 
is that they have their bodies support 
and as it were moulded upon, an int 
frame-work, which is generally made u 
numerous pieces, very various in their { 
and uses, which are called the bones ; at 
assemblage of them, whatever their mot 
tion, constitutes the skeleton. y 
Seeing the great diversity of forms and h 
in the innumerable races of animals const 
this great group of living beings, se 
specially appointed to a the wate 
our globe, others to inhabit the marsh ang 
swamp, whilst others again tread the firm § 
. 
_s 
the regions of the thin air; and that 
the diversified shapes of Fishes, Reptil »B 
and Mammifers, we are prepared, @ priori 
a 
4 
