422 REPORT—1840. 
The next best to these three, are the sulphate of zinc, the 
muriate of magnesia, and arsenious acid. 
The following also possess tolerably fair preserving properties, 
but are by no means so good as those already mentioned. They 
may be recommended in cases of emergency, as temporary ex- 
pedients, and some of them will probably prove more efficient 
when used in combination with others, than when employed 
singly: sulphate of magnesia, sulphate of potash and alumina, 
(common alum,) sulphate of zinc, muriate of ammonia, sulphate 
of potash. It is well known that corrosive sublimate is a per- 
fect preservative of animal substances, but this salt renders the 
flesh so very hard, that singly it is unsuited to the purposes of 
natural history. Added in small proportions to other solutions, 
which render the objects too soft, it will probably be tound of 
essential service; as well also in preventing the formation of 
the flocculent matter which occurs in several of them. 
Prepared naphtha, in the proportion of one part naphtha to 
seven of water, produces a favourable result, but when used more 
highly concentrated the specimens are rendered tough. The rapid 
evaporation of this substance is an objection to its use. 
The effects produced by oxalic acid, and acetic acid, are pe- 
culiar ; they seem to have decomposed the skin and cellular 
membrane of two small fish immersed in them, but to have left 
the muscle untouched. The consequence has been that these 
animals have fallen to pieces, but the separate fragments are 
well preserved, more especially in the acetic acid. 
-A few drops of kreosote added to water preserves the objects, 
but they become stained of a dark brown. The following sub- 
stances appear to be wholly unfit for the purpose, and no further 
trial need be made with them: carb. ammonia, chloride of potash, 
muriate of barytes, muriate of lime, nitrate of ammonia, nitrate of 
strontian, nitrate of barytes, nitrate of soda, nitrate of ammonia 
and magnesia, phosphate of soda, sulphate of soda, sulphate of pot- 
ash, sulphate of iron, sulphate of copper, rough pyroligneous acid. 
2nd. Results obtained with Vegetable Substances.—The suc- 
cess obtained with vegetable substances has been very slight. Spe- 
cimens were immersed in each solution, as in the case of the ani- 
mal substances. None of the salts seem likely to turn out fa- 
vourably in simple solution, unless it may be the sub-carbonate 
and bi-earbonate of potash. In naphtha and acetic acid the spe- 
cimens are preserved, but in the latter they lose their colour and 
assume a reddish tinge. 
P.S. It does not appear from the memoranda that the carbo- 
nates of soda are among the list of substances tried ; but I have 
found that the preserving properties of the common soda of the 
shops are decidedly good on animal substances. 
J. S. Henstow. 
