(1.) As to uniformity of size. Dr. Richardson, of Philadelphia, and others, believe that "the variations above and below the standard size of corpuscles from any par

N the 16th of Decem- ticular animal are comparatively slight in ber, 1878, Prof. Els- fresh blood;" while most microscopists berg, M. D., read hold, with Dr. Woodward, of the U. S. before the New York Army, that "the truth is that not only do Academy of Sciences the individual corpuscles in every drop of a Paper on the Struc- blood vary considerably in size, but as ture of Colored Blood might be anticipated, from this very fact, Corpuscles, of which the average size obtained by measuring a the following is an limited number of corpuscles (50 to 175, abstract:* still more in the case of but 10 to 50, as usually practiced) varies considerably, not only between different individuals, but also between different parts of the very same drop of blood." This point is sometimes of the greatest possible importance in criminal cases. Dr. Elsberg found in every person's blood that he examined some red corpuscles as small as, or smaller than, the 1-3848, and some as large as, or larger than, the 1-2678 of an inch in diameter (i. e.,.0066 and His own success he ascribed to the .00948 mm.), with transitional sizes between method which he pursued, viz: mixing a these; but in each specimen the majority drop of fresh blood with a drop of a 40 per of red corpuscles were of about one size, cent or 50 per cent saturated solution of which, though differing in different specibichromate of potash, and examining with mens, was most frequently between the high power (1,000 diameters or over). His 1.3750 and the 1-3000 of an inch, i. e., investigations have determined some points .00676 and .00845 mm. The colored blood in addition to the structure. These are:

In the course of some introductory remarks, he stated that the discovery of red corpuscles in the blood was one of the first results of microscopical study over 200 years ago; that since that time no other constituent of the body has been more frequently examined; nevertheless their structure had not heretofore been ascertained.

*Dr. Elsberg's paper will appear in full, with additional illustrations, in the Annals of the New York Academy of Sciences, Vol. I, Nos. 9 and 10, (1879.)

corpuscles of monkeys, dogs, wolves, and some other mammalia, come within theso limits, while those of sheep, goats, cats, horses, and some others, are smaller in size.

(2.) As to variations of shape, Prof. Els- any adult human or mammalian red blood berg has observed changing "rosette," corpuscle, Dr. Elsberg states that as a rule "stellated," and "thornapple" forms, such there is none, but that occasionally there is as are represented in rows c and d of Fig. 1, seen in the interior of such a corpuscle an and the occurrence of indentations and accumulation of matter, which may be inprotrusions like those seen in rows a and b terpretated as a nucleus (such a one as is seen of Fig. 1, which either persist or are lev- in the first corpuscle of Fig. 5). Among eled again; protrusion of knobs, either pe- others, Prof. Stowell's publication in this dunculated or sessile, which sometimes are journal* confirmatory of Prof. Böttcher's so numerous that they surround the body experiments to prove the existence of nucleof the corpuscle like a wreath, represented ated human and mammalian red blood in Fig. 2; decrease of the size of the main corpuscles, is referred to; but Brunn and body by detachment of knobs, (seen at e, others are quoted, according to whom "the Fig. 1, and at a, Fig. 2); vacuolization of appearances produced by both of Böttcher's corpuscles (such as are variously repre- later methods are artificial and optical efsented in Fig. 4), and transformation of fects due to the action of the reagents on many of the portions detached into vacu- the substance of the blood corpuscles." olized globules which increase in size. Such active form-changes settle in the affirmative the question hitherto often discussed and usually decided in the negative, whether or not these corpuscles are composed of living matter possessing contrac- 'Soon after the specimen of blood is ready tility; though Beale says: "They are no for examination, a difference is noticeable more living than cuticle, or the hard horny in the intersity of coloration of the corsubstance of nail or hair is living." Fig. 3 puscles; some are paler than others. There gives an idea of the grotesque shapes sometimes met with from the coalescence of two or more colored corpuscles into chains or other compound forms.

On all of these points and others, Prof. Elsberg has given an extraordinarily complete account of the literature of the subject. In the demonstration of the structure we will follow him in detail.

66

is a great difference in the rapidity of "paling" in blood taken from different persons, even in blood of the same person taken at different times and with different (3.) The much vexed question of an in- strengths of the admixed solution of bivesting membrane is at last set at rest by chromate of potash. Usually, in blood of the demonstration that the outer portion healthy persons, mixed with a 40 or 50 per of the corpuscle, although essentially like cent saturated solution, and examined with the inner substance, may be considered high powers, in about an hour, a few of the to be differentiated from the latter, es- corpuscles least deeply colored appear to pecially at the periphery of the disk, where have become somewhat granular in their it constitutes an encircling band of uniform interior. Soon the granules or dots seem thickness (as is represented in the first two more distinct; short conical thorns or more corpuscles of Fig. 5), or sometimes (as delicate spines appear to issue from one or shown in the last corpuscle of Fig. 5) as two of the largest of them; and on close though it were formed by a wreath of inspection and focussing some appear to be beads, each bead separated a little from its connected by irregularly concentric filaneighbors on the string. From this appearance, it is not to be wondered at that so many careful observers have hitherto ascribed to colored blood corpuscles the possession of a separate investing membrane.

(4.) As to the presence of a nucleus in

ments. In the course of five minutes more, a complete network is distinctly seen in the interior of one or more corpuscles, and what at first appeared to be granules turn out to be thickened points of intersection

"American Journal of Microscopy,” June, 1878, page 140.

stage; two still show traces of a network, there is some detritus, the lowest figure on the left represents a so-called "ghost," and the highest on the right a corpuscle out of the interior of which a considerable mass of matter has been protruded.

of the threads forming this reticulum. All detritus, accumulates. In Fig. 6 an atthe corpuscles represented in Fig. 5, and to tempt has been made to depict the appearsome extent those of Figs. 3 and 6 show ance of some of the corpuscles at this this network. The dots or points of intersection are irregularly shaped and vary in size. Radiary threads of the network terminate at the periphery of the corpuscle either with thickened ends connected by threads, as in the last corpuscle of Fig. 5; or, what is more usual, with terminal points It appears as though the network is most lost in an encircling band of a uniform plain in corpuscles that have suffered either thickness, often greater than either the in- not at all or but little from detachment of a terior threads or most points of intersec- portion of their substance. The active tion, as in the first two corpuscles of Fig. changes of indentation and protrusion have 5. As the "paling" progresses, an increas- usually disappeared in a large number of ing number of corpuscles show the interior corpuscles by the time "paling" has sufnetwork, identical in construction with the ficiently progressed to render the interior network discovered by Heitzmann* in amoe- structure visible. Some corpuscles permanba, colorless blood corpuscles, and other ently retain scalloped and knobbed forms, living matter of the body-a discovery while the majority are finally more or less which Dr. Elsberg has brought to the at- rounded off; but the play of changing shape tention of the American Medical Associa- of many corpuscles is going on at the tion more than three years ago.† Grad- same time that their network is seen. ually an interior network structure becomes After a while, further "paling" stops, visible in nearly all the corpuscles in the and the network structure of all corpusfield except the smallest, which appear cles which show it remains visible indefinmore or less compact. Some movement itely long." Some blood corpuscles show takes place in the network, for sometimes it which have been preserved for nearly the threads change in length and perhaps three years. in thickness, and the dots change their position and their size. In the course of another half-hour or hour, the network becomes less distinct in the palest corpuscles, and in these gradually fades away. Then, for some time, the network remains visible in nearly all corpuscles, except those that are too pale or too small; vacuoles, one or more, appear in many of the latter, while on the power of dilute solutions of bithe former occasionally show indications of irregularly massed matter in their interior, though usually nothing is seen of them but double-contoured rings, which have been called their "ghosts." During this time, also, a quantity, sometimes quite large, of

The colored blood corpuscles of lower animals have essentially the same intimate structure as that described in man's. Dr. Elsberg has detailed his observations of those of the ox and the newt-the one an example of the unnucleated, the other one of the nucleated corpuscles.

In conclusion, some remarks are made

chromate of potash to preserve the most delicate animal structures. Heitzmann's views of contraction and extension of living matter are then presented, illustrated by schematical drawings copied from this investigator's publications in Vienna and in this country. These views are shown to *"Bau des Protoplasmas," Sitzungsberichte der have materially enlarged the bounds of Wiener Akademie der Wissenschaften, Vol. 67, human knowledge of the constitution of (1873), Div. III, p. 100. living matter, and are here used to explain the form changes of colored blood corpuscles.

"Notice of the Bioplasson Doctrine," Transactions of the American Medical Association, Vol. XXVI, (1875), p. 157.

Artificial Crystals of Gold and Silver. bag. The strength of the battery current

IN

BY ALBERT H. CHESTER.*

is controlled by a coil of wire arranged as a rheostat, a clamp terminating one of the N casting bars of pure gold for the battery wires, enabling the operator to inmanufacture of foil, traces of crystalli- clude a greater or less number of coils in zation may often be observed upon their the circuit. The necessary conditions being upper surfaces, and sometimes distinct fulfilled, on completing the circuit the gold crystalline forms. These are generally sim- is gradually dissolved from the roll, and ple triangular faces slightly raised, very deposited on the bottom of the dish in similar in appearance to specimens some- bright crystalline flakes, having the appear. times found in nature. Occasionally sev-ance of feathers or fern leaves when exameral faces of the octohedron may be seen, ined under the microscope. Fig. 1 shows the edge in some instances being half an one of these crystals magnified one huninch in length, and quite sharp and well dred and fifty diameters. At first sight, defined. The purer the gold is, the more likely the crystals are to form, and they are oftenest seen when the bars are cast from that which has been previously crystallized by the battery process described below. The presence of a very small amount of copper seems to prevent it entirely, and the surface of the bar is quite smooth. It is perhaps worthy of notice that the forms observed are always triangular and never hexagonal, as is so frequently the case with natural crystals of gold. They do not seem to be distorted or this appears to be like certain natural crysflattened at all. Neither do the dendritic forms so common in nature, and now quite easily obtained artificially, appear on the surface of the bars.

Fig. 1.

tals occasionally found, and the arborescent forms of other isometric minerals. But all such crystals that I have seen have invariably the angle of 60° between the side ribs The precipitation of gold from solution and the midrib, making an angle of 120° by the aid of a battery is a well known between the two sets of ribs. Gold, silver process in the common operation of elec- and copper all show this characteristic, tro-gilding, but to deposit it in the crystal-which is particularly well illustrated in the line form is a process of comparatively re- crystals described by Professor Vom Rath cent date, having been patented in 1860, as a method of preparing gold for dental purposes. The process is briefly as follows. A solution of chloride of gold and ammonium is placed in a shallow dish coated with heavy gold foil, which is connected with the zinc plate of a large Daniell's battery. Near the top of the solution, and connected with the copper plate of the battery, a roll made up of thin strips of pure gold is suspended, enclosed in a muslin

*The original paper on artificial gold crystals appeared in the "American Journal of Science" for July, 1878.

in the last volume of Groth's "Zeitschrift für Krystallographie." This arrangement of the ribs into two sets, each making an angle of 60° with the midrib, is very beautifully shown in the arborescent crystals of copper, sometimes formed in connection with the Hunt & Douglas process for separating that metal from its ore. It is quite difficult in the case of these artificial crystals to measure their angles, because the midrib is usually more or less curved, and the whole form presents great irregularities. It can only be done approximately for a single crystal, but by making a large number of

measurements this difficulty may be in part traces of this structure may be detected in overcome. The figure above shows a crys- the gold crystals, and in some cases sharp tal much like the natural ones, the angle on pointed terminations may be seen, which the left of the midrib being about 59°, and are probably octohedral. on the other side 61°. Such crystals are not If a film of amalgam is allowed to form often found. Fig. 2 represents a crystal on the surface of a piece of pure gold, and such as is most often seen, where the angle on one side is 41° and on the other 79°. The

the mercury be then driven off by heat, traces of crystallization may sometimes be observed, a network of indistinct crystals remaining. To accomplish this the gold should be perfectly pure, and the heat applied very gently at first. With the greatest pains, however, the result is not always, or even often, satisfactory. The surface is generally left in an amorphous condition, or at best covered with angular depressions. Very rarely, and under conditions not fully understood, the crystallization is distinct enough to be recognized as such. But distinct though minute crystals of gold amalgam may easily be obtained if the mercury is dissolved out with dilute nitric acid, inaverage of fifty measurements of these stead of being driven off by heat. A series crystals taken at random is on one side of measurements on a number of these

Fig. 2.

It is noticeable that the same angles are carried out in each crystal, no matter how many branches it may have, and the crystal shown in Fig. 2 was selected to illustrate this fact.

These crystals are also curious in being

Fig. 3.

so perfectly flat. Fig. 2 was drawn under crystals proves them to belong to the hexa power of 300 diameters without any agonal system, having in general the form change in focus. This is very unusual in shown in Fig. 3. The average of fortycrystals of the isometric forms, where eight measurements of the prismatic angle faces and angles can generally be seen with is 119° 53', the six angles of the most pera low power. Under a still higher power, fect one found measuring as follows: