PHOTOGRAPHY. 339 
M. Mialhe has modified this mode of separation, he prefers em- 
ploying five or six washings, with four or five grammes of ether, perfor- 
formed by trituration of the crystals previously pulverised, the morphia 
being thus set at liberty it is easy enough to dry and weigh it. 
M. Aubergier states that, the separation of the narcotine by washing, 
and by decanting, gives much quicker results, and in the greater number 
of cases, quite as certain and as exact as the treatment by ether. And 
he adds, that in case of adopting the latter method, the operator must 
not content himself with seven or eight washings by four grammes of 
ether as there is a risk very often of leaving a considerable portion of the 
narcotine undissolved. In this case, the washings with ether must not 
cease until the insoluble residue no longer diminishes in weight, a 
gramme of ether will only dissolve about five milligrammes of narco- 
tine. 
M. Aubergier says he has repeated the washing sixty times, and em- 
ployed 230 grammes of ether in the analysis of an opium which con- 
tained 19*153 of narcotine for fifteen grammes. 
It appears then, he says, that morphia, instead of depositing itself 
in voluminous crystals, is granulous, gives a pulverulent precipitate, 
although crystalline, which is easily held in suspension in water, and 
carried away by washing. The mixture of morphia and narcotine may 
be treated by a solution of caustic potash, containing a decigramme of 
alcohol per gramme of water. I have ascertained, he says, that four 
grammes of potash are sufficient to dissolve one gramme of morphia. 
The weight can be calculated by the deficiency, after having washed, 
dried, and weighed the residue of the narcotine. 
Independently of the morphia and of the narcotine, M. Aubergier 
has found in indigenous opium, codeine, thebaine, narceine, meconine, 
meconic acid, caoutchouc, and oily and resinous matters, already 
enumerated by Pelletier. "But narcotine, according to Professor de 
Clermont, exists in greater quantity in the white poppy than in the 
purple poppy. 
PHOTOGRAPHY. 
Photography is an affair of the present century. Its annals cover 
scarcely sixty years, and may be divided into three distinct periods : — 
The first extending from the time when science partially revealed the 
fascinating secret of light-printing, till the independent and valuable dis- 
coveries of Mr. Fox Talbot gave the world an art of sterling utility, where 
it had before possessed only a few curious experiments ; the second com- 
prising the years when, protected by Mr. Talbot's care, and in a great de- 
gree popularized by the restrictive powers of his patent, the art made slow 
advances to maturity ; the third reaching down to the present time, from 
the date when the art somewhat ungraciously burst away from the con- 
