Dried Plants

Dried plants are apt to be destroyed by insects, and large collections would soon become the prey of the larvae of Anobium, Ptinus, etc, were not the precaution taken to protect them against the attacks of these pests.

Certain persons are content to keep their plants in tightly closed cases in which they place phenic acid,'camphor; or oil of thyme. Others, once or twice a year, place their packages of plants in a box especially constructed for the purpose, and therein impregnate them with the vapor of sulphidfe of carbon. How dangerous- it is to handle this substance is well known, and it should be used with great caution. The sulphide box should be lined with zinc, and should be closed hermetically by a well-adjusted cover, whose prominent flange enters a gutter, which may be filled with water, and which is affixed to the upper part of the box. After placing a vessel containing a certain quantity of sulphide of carbon at the bottom of the box, the packages are put in place, each being partially opened, so that the vapour disengaged may penetrate everywhere. After the box is closed, it should remain so for several days, after which the cover is removed, and the packages are exposed to the air until the odour of the sulphide has entirely disappeared.

There is a process of preservation which is more generally employed, and which consists in immersing the specimens in the following solution: -

75 per cent, alcohol .. 1 qt. Bichloride of mercury .. 1 1/4 oz.

This liquid is a very violent poison, so the use of it requires great precaution. The following formula is sometimes preferred, because the sublimate preserves its properties more intact: -

90 per cent, alcohol .. 1 qt.

Water ..... 2 1/4 oz.

Bichloride of mercury .. 1 1/4 oz.

Muriate of ammonia . 3/4 oz.

The bichloride is dissolved in the alcohol, the muriate in the water, and the two solutions are mixed:

The plants are immersed in the liquid as follows: A deep porcelain plate of rectangular form, and a little larger and wider than the herbarium paper, is filled with the solution and placed upon a table between a package of plants to be poisoned and a package of driers. Then the tickets are detached from the first specimen, so that they may not be ruined by a stay in the alcohol, and, as a greater precaution, in order to prevent any soiling contact, they are fixed with pins so that they project externally upon a wrapper. A good supply of wrappers should be within reach. This wrapper thus prepared is placed upon a drier, and then, with wooden or whalebone nippers, a Fig. 264, the specimens are seized and immersed in the liquid. Nippers made of metal should never be used for this purpose. The form figured is the one adopted at the Museum of Natural History, and can be easily made by any one for himself.

After the specimens have remained in the liquid for a short time, they are taken out with the nippers and allowed to drain; then they are placed in the cover, which is closed and covered with a drier. The same operation is performed on the rest of the specimens. As soon as a large enough package has been formed it is put in a well-aired place, so as to permit of the evaporation of the alcohol. At the end of 24 hours it is necessary to replace the damp driers by dry ones. A longer stay in them would blacken the specimens.

It must not be thought that the specimens thus prepared are for ever proof against the attack of insects. The herbarium should be often inspected, and a few drops of preservative liquid be thrown upon such specimens as are beginning to be attacked. This operation may be very easily performed with the bottle represented in b. This is closed with a rubber stopper, through which pass two glass tubes, one for the passage of the liquid and the other for the entrance of air.

Certain families of plants are much more sought after than others by insects. As a general thing, fleshy plants and those that contain starch are the first ones eaten; the grasses, ferns, and mosses, on the contrary, are very rarely attacked. After the plants have been poisoned, it only remains to arrange them in the herbarium. To this effect, they are fixed upon simple sheets of strong, sized paper, in such a way that they will hold well. Thus prepared they art put in wrappers. The mean dimensions of the mounting paper are 12 x 18 in.

For filing the specimens, use small strapsof gummed paper arranged here and there In such a way (p, Fig. 265) as to hold nil the parts, without, however, concealing them. Instead of•trap) some persons use pins, but the use of these is more difficult, and the; hare the drawback of breaking the delicate parts of plants by their contact. The specimens must not be glued to the paper, but should be detachable at will, so that they can be thoroughly examined when necessary. Several species should never be fired upon the tame sheet.

Large specimens, the lichens, with their support, and certain fungi can be fixed only upon very strong paper or even upon cardboard, and it is sometimes indispensable to sew them on with cord- In order to prevent them from injuring the neighbouring plants in the package, good cushions of soil paper should be interposed. In al cases sufficient space should be reserved at the bottom of the sheet for the reception of the labels. To the left is placed that of the Collector or of the person from whom the specimen was received. This label should always be carefully preserved, for it is the one that must give authority in the cue of doubt. It should bear the number and the notes taken in the memorandum book. When it is a question of exsiccati, that is to any, of collections of which several examples exist, the numbers permit of easily finding the names of the plants when the latter are described and published. To the right is placed a label by itself sufficiently large to allow bibliographic name. The flowers and fragments that become detached daring the preparation of the specimens must not be registered, but should be preserved in small envelopes, and whenever it is desired to make an analysis, it is better to use them than to injure one's collection.

The sheets filled with specimens are placed in wrappers, and it only remains to classify them by families and put them in packages, which should be arranged in tight cases in a dry place, anil where the temperature is as equable as possible. Care should betaken to allow, nothing to enter the room devoted to the collection that could attract insect!, and never to allow plants to enter it that have not first been poisoned. Several sheets on which are mounted species belonging to the same genus may be enclosed in the same wrapper. To the upper right hand corner of the wrapper should be glued a small, conspicuous ticket bearing the name of the species This renders researches much easier.

Preserving Botanical Speciemens

Preserving Botanical Speciemens.

Preserving botanical specimens.

Preserving botanical specimens.

Conspicuous tickets are also used for the genera, but these are fixed upon simple sheets, so that they can be easily shifted. They must be very distinct from the preceding. They may, for example, be made longer, and of a different colour. -They are usually affixed to the middle of the sheet. The family ticket should be larger still, and also of another colour. It is fixed to the left of a simple sheet.

The herbarium packages should not be too bulky. They are kept between cardboards, fastened together with straps.

An excellent measure taken at the herbarium of the Paris Museum consists in placing the species, according to their country, in wrappers bearing labels of various colours, corresponding to the 5 parts of the world. White indicates European species, yellow represents those of Asiatic origin, blue is for Africa, green for America, and red for Oceania. This arrangement permits of easily finding the species in which one is interested when he is making researches upon the flora of a region. Besides, it shows at a glance the geographical distribution of each species, genus, and family.