Chemistry and Physics. 119 
from which the third baryta salt was ern yielded a substance 
fusing at 10°~12° and having the formula C1sH1isQ2, which ma y pos+ 
sibly be the aldehyd of pelargonic acid. The fatty acids in combina- 
tion with baryta were separated from each other by the method of 
partial precipitations Pag by Heintz with so much success in his 
examination of hum n fat. In this manner five homologous acids were 
cetyl. Heintz terms these salts, cocathal, myristathal, cetathal, pal- 
oe and margathal. Their formulas are 
argathal or margarate of cetyl, Cs2H3s30+Cs4Hss0s 
fac or palmitate of ets C32H3s30+Cs2H310s 
Cetathal or cetate of cetyl, C22Hs3s0+Cs0H290s 
“Myristathal or myristate of cetyl, C32Hss0+C2sH290s 
ene or cocinate of cetyl, Cs2Hss0+C2cH2s0s 
Besides these compounds, however, spermaceti contains probably a 
small quantity of olein which is doubtless derived from the oil from 
which the spermaceti has crystallized. A second neutral substance 
Was also obtained in small quantity : it was soluble in ether but only with 
great difficulty so in alcohol ; its formula eipearee to be C2sH26Qs. 
fir praktische Chemie, lvii, 30. 
Korth Positive eine Pictures. sims Martin has given a 
of producing directly positive pictures upon glass, which ap- 
Pears to oo rt ue advantages. Two grammes of cotton are to be 
bream n-cotton by a mixture o! pense ipiaencen 90" bar 
and 100 gr. of cal petie acid: the product is to be well washed, dried, 
disso} lved in a mixture of alcohol and ether so that the solution 
and p 
ing the the Slain with iodid Pee sada The ait plate prepared 
— Usual manner and covered with a thin. layer of ‘this solution is to 
dipped before drying into a bath composed of 1 a distilled water, 
Ye of nitrate pg silver and >, of nitric acid, and the few 
camera. It is then to be dipped into a a bat of sulphate 
a bai i rn and afterward stare washed. — je pic cture is now a ve, 
of Stum it “ae a positive. It is to be , covere with a verre 
r dextrin, dried, and. fra upon a backgrou und of black velvet. 
wee bath i is dg of er 00° and eT diluted with 3 vols. 
ton 
temo Seltvaitents we sali of raisins 2 arsenic by the vola- 
of the chl chlorid—already described in this Journal, (xiv, 259)— 
rr has found by quantitative Leys gr that a portion of the arsenic 
= behind in the retort; so that the process can at best be buta 
i F205 auth even from this point of view is inferior 1 to: o-thiat 
att 
ari a a 305. 
